FBI warns key al Qaeda capture could spark attacks

The FBI has warned US law enforcement officials to be on the lookout for signs of "terrorist planning" in light of the recent arrest of suspected September 11 mastermind Khalid Sheikh Mohammed.

In its weekly intelligence bulletin sent out to law enforcement officials across the country, the FBI said the weekend arrest in Pakistan of Mohammed and two other al Qaeda operatives could speed up any attacks that are in the works.

"The FBI assesses that the capture of Khalid Sheikh Mohammed deals a severe long-term blow to al Qaeda's ability to plan and carry out attacks against the United States," the bulletin said.

"However, in the short-term, this apprehension may accelerate execution of any operational planning already underway, as operatives seek to carry out attacks before the information obtained through Mohammed's capture can be used to undermine operational security.

"Law enforcement agencies should remain alert to potential signs of terrorist planning or execution and should report suspicious activity," it said.

In addition to Mohammed, the FBI identified one other man captured as Mustafa Ahmed al-Hawsawi, who is believed to be a key financier of the September 11, 2001 attacks.

The FBI said Mohammed and al-Hawsawi were currently in US custody and had been transported to a secure site outside Pakistan where they are being interrogated.

The bulletin said Mohammed was believed to have played a key planning role in the September 11 hijacked-airline attacks, the bombing of a synagogue in Tunisia in April 2002 and a thwarted plot to bomb US and Western embassies in Singapore in 2002.

Top US officials have hailed Mohammed's arrest but have also warned the nation could not relax its vigilance against terrorism.