Iraq's top diplomat on Thursday said he had "solid information" that Al Qaeda militants were crossing from Iraq to Syria to carry out attacks, warning of a violent spillover that could shake the Middle East.

Foreign Minister Hoshyar Zebari said Baghdad had for years urged Damascus to clamp down on militant traffic as Sunni fighters headed from Syria to aid the Iraqi insurgency.

"Now their direction is the other way around," Zebari told reporters in Baghdad.

"We have solid information and intelligence that members of Al Qaeda's terrorist network have gone to Syria," he said, without elaborating. "Our main concern, to be honest with you, is about the spill over -- about extremist, terrorist groups taking root in neighboring countries."

Zebari also blamed a recent surge of violence in Iraq on the months-long political crisis that has gripped the country. Militants have launched major bombings and shootings at least every three days since the start of June, killing nearly 300 people.