Turkish police say they have foiled a major bomb attack planned against Western leaders scheduled to meet next month in Istanbul. Police arrested at least 16 suspected members of a group they say was linked to the al-Qaida terrorist network.

The governor of the western town of Bursa, Oguz Kagan, says police seized equipment to make remote controlled bombs, handbooks on how to assemble bombs, scores of rifles, and video tapes showing al-Qaida leader Osama bin Laden training militants at a camp in Afghanistan.

Police believe the suspects were planning an attack during a two-day NATO conference scheduled for Istanbul starting June 27. President Bush and British Prime Minister Tony Blair are among a host of western leaders expected to attend.

Turkish police said at least eight other suspected terrorists were detained in simultaneous raids carried out in Istanbul.

Turkish officials said the suspects were members of Ansar al-Islam, but it remained unclear whether they were referring to the northern Iraq-based terrorist group of the same name.

That group was formed in the mid-1990s, mainly by ethnic Kurds based in the mountains separating Iraq from Iran. Iraqi-Kurdish officials say the group has developed strong ties with al-Qaida.

Concerns about the security situation in Istanbul have sharply increased since November when at least 60 people were killed in four separate suicide bomb attacks against British and Jewish targets in the city of 10-million people. Al-Qaida claimed responsibility for the bombings that authorities said were carried out by Turkish nationals.

Last month, a top Spanish counter-terrorism official disclosed that terrorists accused of carrying out the March 11 train bombings in Madrid, also linked to al-Qaida, had held secret meetings in Istanbul to plan the attacks that left 191 people dead.

Turkish police have stepped up cooperation with western security organizations in recent months in a bid to stem the growing tide of terrorist attacks.