BRUSSELS, Belgium - Police detained 14 suspected al-Qaeda-linked extremists yesterday in raids in Brussels and eastern Belgium, including one extremist who allegedly was plotting a suicide attack.

The police sweep came hours before a European Union summit brought together the heads of 27 countries in Brussels, though the site of the purported attack was unclear. Nearly 250 police officers raided 16 locations in the capital and one in the eastern city of Liege overnight, confiscating computers, data-storage equipment and a pistol.

"There was no other choice than to intervene today," federal prosecutor Johan Delmulle told reporters. He said one suspect had recorded what looked like a martyrdom video, including a farewell message.

"It is clear that we have to take the terror threat seriously," Prime Minister Yves Leterme said as he entered the EU summit building.

Helicopters flew overhead and police guarded dozens of motorcades traveling to the summit cordon. The terror-alert level in Belgium was not raised, officials said.

Delmulle said it was unclear where the attack had been planned to take place. Some suspects had traveled to both Pakistan and Afghanistan, and it was possible the suicide bombing might have been drawn up there. One who had recently returned "said goodbye to his loved ones because he could go to paradise with a clear conscience," Delmulle said.

Yesterday's raids were linked to a similar pre-Christmas sweep last year, and Delmulle said the investigation showed at the time "a group of people were in Brussels with the task of committing an attack."

Investigators waited a year before moving in, opting to ferret out the entire cell rather a single part. "It is now clear to all that we were dealing with a real risk," the justice and interior ministers said in a statement. "It is more than likely that an attack in Brussels has been prevented."