Baghdad (AsiaNews/Agencies) – US military leaders in Iraq complain that the Syrians are collaborating with al-Qaeda's plan to destabilise the new Iraqi government and plunge the country into a civil war.

Iraq's top al-Qaeda leaders met in Syria, possibly including Abu Musab al-Zarqawi, who, angered by a post-election lull in violence, a month ago ordered insurgents to intensify attacks, a top US military official said.

An internet audiotape purportedly by al-Zarqawi called on Muslims to jihad (holy war). "God ordered us to attack the infidels by all means . . . even if armed infidels and unintended victims—women and children—are killed together," said the speaker in the tape. Shiites are denounced as US collaborators and killing them is said to be justified.

The call seems to have been heeded. In the first weeks of May, there were 21 car bombings, mostly by suicide bombers, compared to only 25 such attacks in the whole of 2004. Altogether since February, 130 car bombs have either exploded or been defused.

Since April 28, when the new government was sworn in, attacks have killed more than 470 people, including several Shiite and Sunni Muslim clerics, raising fears among US observers that sectarian tensions could ignite a civil war.

Al-Qaeda leaders in Iraq have met at least five times in foreign countries during the conflict, most recently in Syria, according to the senior US military official.

In Washington, General John Abizaid, commander of US forces in the Middle East, said he couldn't confirm or deny reports that the meeting had occurred but noted that "insurgent-inspired" activities are "clearly" taking place in Syria—though without Syrian government collusion.

Asked if he thought Damascus was doing enough, he replied: "No, I do not think the Syrian government is doing enough" to stop militants from entering Iraq from its territory or to prevent it from being used to plan attacks in its neighbour.

Syrian political analyst Imad Fawzi al-Shueibi, who is close to the Damascus government, dismissed the report as "part of an organised campaign against Syria."

"Syria has no interest in [helping] al-Zarqawi," al-Shueibi said. "If al-Zarqawi and his group win in Iraq, they will turn the region into a fundamentalist nightmare."