Norway – Norwegian police set off a controlled explosion of a "bomb-like device" in central Oslo early on the 9 Apr 17 and were holding a suspect in custody in an investigation led by security police. A reporter described a loud bang shortly after Oslo's bomb squad arrived with a remote-controlled robot once the area was cordoned off by police late on the night of the 8 Apr 17. The device, about 30 cm (1 ft) across, had appeared to be capable of causing only a limited amount of damage. Forensics experts will examine fragments to figure out what it was. Police across the Nordic region have been on heightened alert after a truck ploughed into a crowd in Stockholm on the 7 Apr 17. Four people were killed and 15 injured in what police called an apparent terror attack. Norwegian police detained a suspect but declined to give information about his identity. Norway's police security service, PST, said in a tweet it had taken over the investigation from local police. "We're in a very early phase of the investigation," PST spokesman Martin Bernsen said. More details were likely later on the 9 Apr 17. Police took away cordons put up overnight in the Groenland area and residents resumed normal activities, with shops and cafes open. There was no sign of police at the site. The Groenland area, a multi-ethnic neighbourhood that is home to popular bars and restaurants, several mosques, and the city's main police station. The police station is less than a kilometre away from where the device was found.
Spain/France/Basque Fatherland and Freedom (ETA) – Basque militant group ETA has begun handing over its remaining weapons, ending the last insurgency in Europe. At a ceremony in the southern French city of Bayonne, an inventory of weapons, and their locations, was passed to the judicial authorities. French Interior Minister Matthias Fekl hailed the move as a "major step". ETA killed more than 800 people in some 40 years of violence as it sought to carve out an independent country straddling Spain and France. It declared a ceasefire in 2011 but did not disarm. Mr Fekl said the inventory included eight sites, and a police operation was under way to secure them. The caches contain 120 firearms, three tonnes of explosives and several thousand rounds of ammunition, according to a spokesman for the group which mediated between ETA and the French authorities.
What is ETA?
The group was set up more than 50 years ago in the era of Spanish dictator General Franco. Its goal was to create an independent Basque state out of territory in south-west France and northern Spain. Its first known killing was in 1968, when a secret police chief was shot dead in the Basque city of San Sebastian. France and Spain refuse to negotiate with ETA, which is on the EU blacklist of terrorist organisations. The Chairman of the International Verification Commission (IVC), Ram Manikkalingam, said he hoped the 8 Apr 17 handover would help consolidate peace in the Basque region. French police have begun checking the list of sites handed over on the 8 Apr 17. There is also the IVC, set up in 2011 to monitor ETA's progress towards disarmament. However, it is not formally recognised by the French and Spanish governments. In 2014, the IVC reported that ETA had taken some of its weapons out of action, but the Spanish government dismissed the move as "theatrical". The Spanish government does not believe ETA will hand over all its weapons, a government source as saying.
How did we get here?
Slowly, and with many false starts:
ETA's first ceasefire was in 1998, but collapsed the following year. In 2006, it made another pledge to lay down arms that, too, proved to be illusory. In December of that year, it bombed an airport car park in Madrid, killing two people. Four years later, in 2010, ETA announced it would not carry out further attacks and in January 2011, it declared a permanent and "internationally verifiable" ceasefire but refused to disarm. In recent years, police in France and Spain have put ETA under severe pressure, arresting hundreds of militants, including leadership figures, and seizing many of its weapons. ETA's political wing, Herri Batasuna, was banned by the Spanish government, which argued that the two groups were inextricably linked.
Sweden – A lorry smashed into a store in central Stockholm, killing at least four people it was reported on the 7 Apr 17. At least a dozen people were also injured in the incident on Drottninggatan (Queen Street), one of the city's major pedestrian streets on the afternoon of the 7 Apr 17. Swedish Prime Minister Stefan Lofven said it was a terror attack. One man has been arrested, after police released a CCTV image of a person who may be connected to the case. The crash happened at the Ahlens department store just before 1500 hrs local time (1300 hrs GMT). Witnesses say the lorry drove into the front window. Swedish brewery Spendrups said at first that its lorry had been stolen on its way to a restaurant delivery earlier in the day. Later it was reported that the driver was the correct driver of the vehicle and it had not been hijacked and stolen. Much later still the beer company that owned the lorry said it was hijacked while making a delivery to a restaurant. Shots were reportedly fired in another part of the city, but Swedish police told local media there was no connection between the two incidents. The suspect was detained on the evening of the 7 Apr 17 after police released a grainy security camera image of a person of interest dressed in a hooded jacket. A second arrest was reportedly made later. Police confirmed a man resembling him was arrested in Marsta, 40km (25 miles) north of Stockholm. He is being held on suspicion of committing a terrorist crime, the state prosecutor's office said, and is in prolonged detention, according to a police website. The second man, detained in the Hjulsta in the north-west of Stockholm, had links to the man arrested in Marsta, local media reported citing police sources. Swedish police confirmed they discovered a suspect device inside the vehicle. The device was found in the driver's seat, National Police Commissioner Dan Eliasson said, but it was not known whether it was a bomb. Mr Eliasson also said the suspect in custody was from Uzbekistan, 39, and known to security services. The Stockholm truck attack suspect has confessed to a "terrorist crime", his lawyer said at a court hearing in the Swedish capital. Rakhmat Akilov, 39 and from Uzbekistan, admitted carrying out the attack in court and was remanded in custody. A second man is no longer being held as a suspect, according to prosecution authorities, but he will not be released because he already had a deportation order standing against him. Swedish police said Mr Akilov was known to security services. He had been denied residency in Sweden and had expressed sympathy for so-called Islamic State (IS), they said. No group has claimed to be behind the attack. Mr Akilov reportedly ran from the scene of the attack, still covered in blood and glass, and was arrested hours later in a northern suburb of Stockholm. According to reports, he had left a wife and four children behind in Uzbekistan in order to earn money to send home. After applying for residency in 2014, he was informed in December 2016 that "he had four weeks to leave the country", police official Jonas Hysing said. He disappeared and, in Feb 17 was officially put on a wanted list.
Timeline: Vehicle ramming attacks in Europe and the US
14 July 2016, Nice, France: A man drove a lorry for 2km (1.2 miles) through a large crowd gathered to watch Bastille Day fireworks in Nice. Eighty-six people were killed, and more than 300 injured.
28 November 2016, Ohio, United States: An 18-year-old student rammed his car into a group of pedestrians at Ohio State University and stabbed others. Eleven people were injured before he was shot and killed.
19 December 2016, Berlin, Germany: The attack in Berlin killed 12 people and injured 49, when a man drove a lorry through the crowded Breitscheidplatz Christmas market. So-called Islamic State said one of its "soldiers" carried out the attack.
22 March 2017, London, United Kingdom: Six people died and at least 50 were injured when a car mounted the pavement on London's Westminster bridge and drove at high speed through pedestrians. The attacker then entered the parliament complex on foot and fatally stabbed a police officer, before being shot.
23 March 2017, Antwerp, Belgium: A man was caught by soldiers after he drove at a crowd. Knives, a non-lethal gun and a dangerous substance were found in his car - but no-one was injured. Terror charges were later dropped.