Belgium has stepped up security against a possible terrorist attack after arresting 14 suspected Islamist militants and thwarting what police said was a plot to spring an al-Qa'ida suspect from prison.
"There are indications that a terrorist attack could be in preparation," the Prime Minister, Guy Verhofstadt, told a news conference.
Federal prosecutors said the 14 people arrested suspected members of a militant Islamic group had been planning an armed attack to free Nizar Trabelsi, a Tunisian who was arrested in September 2001 for plotting attacks on US targets.
The authorities increased police patrols at Brussels international airport, on rail and metro networks in the Belgian capital and at commercial centres during the busy last-minute shopping period before Christmas.
"They were planning to use weapons and explosives to free him ... These means could be employed for another use," Lieve Pellens, spokeswoman for Belgium's federal prosecutors, told a news conference. She added that investigators were not aware of any other specific plan at this stage.
Ms Pellens said Trabelsi had been arrested in Belgium for planning to attack American targets. He subsequently told a radio station that he had planned to target a Belgian air base which was thought to be used by the Americans.
Belgium hosts the headquarters of Nato, the European Union institutions and the offices of a range of multinational companies. ReutersReuse content