Terror alert in Brussels amid fears of Paris-style attacks
Armed police and soldiers are patrolling the streets, subways are closed and many shops have shut their doors in the Belgian capital Brussels as the government issued a warning over possible Paris-style terror attacks.
At least one suspect from the deadly Paris attacks just over a week ago is at large and was last seen crossing into Belgium.
Belgian prime minister Charles Michel said the decision to raise the threat alert to its highest setting was taken "based on quite precise information about the risk of an attack like the one that happened in Paris ... where several individuals with arms and explosives launch actions, perhaps even in several places at the same time".
The Belgian federal prosecutor's office said several weapons were discovered during the search of the home of one of three people arrested in connection with the Paris attacks, but said no explosives were found.
Authorities across Europe, the Middle East and the US are trying to determine how a network of primarily French and Belgian attackers with links to Islamic extremists in Syria plotted and carried out the deadliest violence in France in decades, leaving 130 people dead.
A new potential link has emerged in Turkey, where authorities said they detained a 26-year-old Belgian suspected of connections to Islamic extremists, and possibly to the Paris attacks.
Reports identified him as Ahmet Dahmani, and said he is suspected of having explored areas in Paris that were targeted in the attacks.
Belgium's national crisis centre has raised its terrorism alert for the Brussels region to Level 4, which indicates a "serious and immediate threat".
Belgium's special security cabinet held an emergency meeting on Saturday morning.
Brussels was the home of Abdelhamid Abaaoud, the suspected organiser of the November 13 Paris attacks, and Belgium has filed charges of "participation in terrorist attacks and participation in the activities of a terrorist organisation" against three other suspects.
At least one Paris attacker, Salah Abdeslam, crossed into Belgium the morning after the attacks. Paris officials say they have no firm information on Abdeslam's whereabouts, including whether he was in the Brussels area.
Brussels, a city of more than one million, is home to the headquarters of the European Union, the Nato alliance and the offices of several multinational corporations.
Residents were told to avoid gatherings, train stations, airports and commercial districts. Service has been halted on the Brussels Metro, as well as on tramlines that run underground.
Many stores and shopping centres in the capital have shut their doors on what would normally have been a busy weekend shopping day in the lead-up to the Christmas holidays.
The Royal Museums of Fine Arts of Belgium closed for the weekend, and a Saturday evening concert by French rocker Johnny Hallyday was rescheduled for next March.
Brussels Airport, which is not in the Brussels administrative region, reported normal operations on Saturday, but external communications manager Florence Muls said special attention was being paid to security.
"We urge the public not to give in to panic, to stay calm. We have taken the measures that are necessary," the prime minister said.
Concerns about Europe's porous borders prompted interior and justice ministers meeting in Brussels on Friday to promise tightened controls to make it easier to track the movements of jihadis with European passports travelling to and from war zones in Syria.
Paris prosecutors said Friday that they had determined through fingerprint checks that two of the seven attackers who died in the bloodshed November 13 had entered Europe through Greece, an entry point for many of the hundreds of thousands of migrants seeking asylum in Europe.
The five other attackers who died had links to France and Belgium. One of the seven dead has not been identified, while a manhunt is under way for one suspect who escaped, 26-year-old Abdeslam. French police stopped Abdeslam the morning after the attacks at the Belgian border but then let him go. His brother Brahim blew himself up in the Paris massacres.
The suspected ringleader, Abdelhamid Abaaoud, was killed in a raid on Wednesday on an apartment in the Paris suburb of Saint-Denis.
Seven of the eight people detained in that raid have been released, the Paris prosecutor's office said.
The US Embassy in Belgium has urged Americans in the country "to shelter in place and remain at home", while the US European Command issued a 72-hour travel restriction for US military personnel on travel to Brussels.
On Saturday night, a relative calm descended on the city centre, where restaurants and beer bars would usually be teeming with business.
On Brussels' central square, the Grand Place, tourists snapped selfies as a green army truck full of soldiers pulled up next to a lit Christmas tree.
Some restaurants and bars shuttered their doors, while others remained open, defying advice from the mayor Yvan Mayeur to close for the night.
In Paris, the annual Christmas market along the Champs-Elysees, shut down after the attacks, reopened in time for the weekend.
Although crowds seemed smaller than usual, people lined up on the cobblestones to ride a huge ferris wheel at the Place de la Concorde, lit up in red, white and blue.