Brussels on level four security alert after Paris attacks

No weapons or explosives were found during the searches on Sunday, Mr van der Sypt said.

One of the men is believed to be Salah Abdeslam, who was in Paris last weekend and whose brother was one of the suicide bombers in the attacks. The key subject of Belgium’s national manhunt, however, Salah Abdeslam, remained at large.

Belgian security forces patrolling certain neighborhoods in Brussels are telling people to stay away, shortly after the government maintained the terror threat alert at its highest level for the capital.

The European Union and North Atlantic Treaty Organisation, which are based in Brussels, both said they would increase security and urged non-essential staff to work from home on Monday.

“We fear an attack like in Paris, with several individuals, perhaps in several places”, Prime Minister Charles Michel, who chaired a meeting of the country’s national security leadership, said at a press conference in Brussels.

Guests at the Radisson Blu Hotel were told to stay in their rooms and residents of the area were told to stay indoors until further notice.

Earlier Sunday, the mayor of one of Brussels’ many municipalities told Belgian media that the capital is still facing a grave threat because of the likelihood of there being terrorists connected to the Paris attacks there.

Many Belgians responded in light-hearted fashion by tweeting pictures of cats under the hashtag #BrusselsLockdown.

However Belgian Interior Minister Jan Jambon has insisted “the situation is serious but under control” as government agencies are “literally working day and night ” to deal with the threat.

Meanwhile, the BBC understands that another of the suspected attackers – pictured in a new French police appeal issued on Sunday – arrived in Greece under the name of M al-Mahmod.

He added that he would go ahead with a December visit to Paris for United Nations climate talks and called on other countries to show similar resolve.

French president Francois Hollande will meet British prime minister David Cameron in Paris today and will travel to Washington and Moscow later in the week to push for a stronger global coalition against IS.

He will host Britain’s David Cameron on Monday before holding talks with Obama, Germany’s Angela Merkel and Russia’s Vladimir Putin later in the week.

In Paris, defence minister Jean-Yves Le Drian said a chemical or biological attack “was among the risks” faced but that all possible precautions had been taken.

People in Brussels were “very nervous”, Cendrowicz said.

Police have undertaken an array of raid operations to ensure Belgium’s safety as it is likely to experience a serious Paris-like attack anytime.

During the raids, Belgian media vowed to stop reporting details of the operation as it was ongoing.

Authorities told VOA’s Jamie Dettmer that Michel’s warning was based on “quite precise information”, including the possibility that chief Paris attack suspect Salah Abdeslam could be planning a suicide attack in the city.