BAGHDAD: Iraq has indefinitely halted all flights to and from Syria and closed a border crossing with Iran.

The moves came as the government prepares for a new security crackdown by US and Iraqi forces aimed at crushing violence in the capital and surrounding regions.

Hassan al-Sunneid, a member of the parliament Defence and Security Committee, said the action "was in preparation for the security plan".

The moves are being seen as a signal to both countries not to interfere in Iraq's affairs.

Syria is believed to be harbouring former Baath party officials who support the Sunni insurgency and has been accused of allowing foreign fighters to slip across its border with Iraq.

And US officials claim Iran smuggles weapons to Shi'ite extremists who have killed Americans, and provides militia with training and support.