He said the threat level would be reassessed Sunday afternoon.All metro stations remained closed and the public transport authority’s Facebook page said buses would operate but some tram routes are affected.“The analysis shows indeed a serious and imminent threat that requires taking specific security measures as well as specific recommendations for the population,” the interior ministry crisis center said in a statement announcing the alert upgrade to 4.Soldiers were deployed outside many hotels and tourist spots throughout the capital. Many stores closed early Saturday and police asked many bars and nightclubs to shut for the night.Meanwhile, Belgian officials confirmed that Ahmed Dahmani, 26, a Belgian national of Moroccan descent with ties to Abdeslam, was arrested in Antalya, Turkey on Saturday morning.“Dahmani was known to us; we knew he could have left for Syria,” Eric Van Der Sypt, a spokesperson for the Belgium’s prosecutor’s office said. “The best possibility for him, I would say, is to surrender himself to the law enforcement authorities,” Van Der Sypt said.One of those detained by Belgian police Thursday in relation to the Paris attacks has been charged with “participation in terrorist attacks and participation in the activities of a terrorist organisation.”Abdeslam, who lived in the Molenbeek district of Brussels, was not among those arrested during a dramatic police raid in the Paris suburb of Saint-Denis Wednesday morning and has not been identified as one of the three people killed during that operation — one of whom was suspected attack ringleader Abdelhamid Abaaoud. Abaaoud’s cousin, Hasna Aitboulahcen, was also killed during the raid. The third body has not yet been identified.There were several unconfirmed reports of Abdeslam’s whereabouts Thursday and Friday. Belgian newspapers Het Laatste Nieuws and La Libre Belgique reported that Abdeslam had been seen in the Brussels neighborhood of Anderlecht on Thursday night, but police officials would not confirm those accounts.On Sunday, Mohammed Abdeslam made a televised appeal for his brother to turn himself in to authorities.“I would rather see my brother in prison than in a cemetery,” Mohammed Abdeslam said in an interview with Belgian national broadcaster RTBF. Osman Sert, a senior press adviser to Turkish Prime Minister Ahmet Davutoğlu, said Dahmani was arrested because “he has links with Paris attacks.”An Italian senior police officer who spoke on condition of anonymity said “Dahmani is a connection of Salah Abdeslam, the man currently on the run.”Italian police confirmed that Abdeslam traveled by car with a Belgian plate on a ferry from Bari, Italy, to Patrasso, Greece, on August 1 with Ahmed Dahmani. The two returned to Italy from Greece on August 5. After an inquiry, the police discovered that on the day of his departure Abdeslam bought a second ticket with a person who had the initials A.D., which stands for “Ahmed Dahmani,” the Italian official said.The link between Dahmani and the attacks was established because he “had communication with the terrorists who committed the Paris attacks,” a Turkish official told POLITICO.The Belgian government recommended that people avoid crowded places in the Brussels region, such as concerts, major events, train stations and airports, public transportation or places with many stores. Many public events during the weekend were canceled.The U.S. embassy in Belgium urged U.S. citizens living in Brussels to stay at home while the state of high alert was in effect. Brussels spent a second day under lockdown Sunday as law enforcement continued their search for Salah Abdeslam, who is suspected of renting a car for the Paris attacks.The Belgian government raised the terror threat for the Brussels region to its highest level early Saturday morning, warning the risk of an attack is “serious and imminent” and urging citizens to avoid crowded places but remain calm.Prime Minister Charles Michel said the decision was taken because of “relatively precise information that a risk of attack could take place as it did in Paris.” Belgian authorities urged people to “facilitate and respect security checks,” to avoid spreading rumors and to follow only official information from the Belgian authorities.Local authorities were alerted at 1 a.m. and recommended to shut down the metro and cancel events over the weekend, said Peter Mertens, spokesperson for the crisis center.The threat level remained at 3 for the rest of the country. Authorities last raised the threat level to 4 in December 2007.Law enforcement officials had intensified their search Friday for Paris attacks suspect Abdeslam, acting on intelligence and reports that he was in the Belgian capital.“I confirm Salah Abdeslam is not among the people we arrested, he is still on the run,” said Van Der Sypt, the Belgian prosecutor’s office spokesman.“We have two possibilities: Either he failed [in Paris] and now has to succeed [in a terror attack],” or “he got scared in Paris and ISIS is not very amused with this.” Mohammed’s other brother, Ibrahim, blew himself up in the Paris attacks. Mohammed told RTBF he was unaware that Salah and Ibrahim had become radicalized.“When your brother starts praying, it’s not neccesarily a radicalist change,” he said. “When your brother tells you that they will stop drinking, it’s not a radicalist change. They were only people that wanted to become better, from our point of view, and be a bit more respectful in their religion.”This story was updated to add the latest information. It was also corrected to reflect the fact that the Belgian government did not tell citizens to stay home, but rather to avoid crowded places.