Philippine authorities have arrested three Middle Eastern men suspected of involvement in a plot to bomb the American embassy and three other foreign missions in Manila, officials said Thursday.

"There is a high probability that they are involved in some kind of plan to sow trouble," Executive Secretary Eduardo Ermita told reporters on the sidelines of an annual anti-terrorism and business security conference.

One of the militants was arrested in Manila and the two others were captured separately in the southern Philippines recently.

Ermita refused to provide details, but two senior Filipino security officials told The Associated Press that investigators were verifying intelligence information that the three may have been involved in an active plot to bomb the U.S., British, Australian and Israeli embassies in Manila.

The officials spoke on condition of anonymity because they were not authorized to talk to the media.

Efforts to obtain comment from the four embassies were not immediately successful, with Australian officials saying they could not comment on security issues.

Authorities believe the three may have links with the Indonesia-based militant group Jemaah Islamiyah and the Abu Sayyaf, a small but violent southern Philippine-based group blacklisted by Washington as a terror organization.

Both groups have been blamed for deadly bomb attacks, including the February 2004 bombing of a ferry in Manila Bay that killed 116 people in the country's worst terrorist attack.

Funding for the plot had been secured, indicating that a planned attack against the embassies may have already been in an advanced stage, one of the security officials said, adding that all the embassies concerned have been notified.

At least one of the three suspected militants identified himself as Jordanian. Ermita said all three were Middle Eastern, but investigators were still trying to verify their identities.

One of the security officials said there was no indication that the newly uncovered terror plot involved a direct threat against President Gloria Macapagal Arroyo. Military and police officials recently said, without elaborating, that they had uncovered an assassination plot against the president by terrorists.

The Philippines is a key Washington ally in its global war on terrorism. It has allowed U.S. counterterrorism troops to arm and train Filipino soldiers battling Al Qaeda-linked militants in the country's south, scene of a decades-long Islamic separatist insurrection.