BAGHDAD, Iraq — Iraq indefinitely halted all flights to and from Syria and closed a border crossing with Iran as the government prepares for a new security crackdown aimed at crushing violence in the capital and surrounding regions, a member of Parliament and an airport official said yesterday.

The airport official said flights to and from Syria would be canceled for at least two weeks and that service had been interrupted on Tuesday. The official spoke on condition of anonymity because he was not authorized to reveal the information.

Hassan al-Sunneid, a legislator and member of the parliament Defense and Security Committee, said the move “was in preparation for the security plan. The state will decide when the flights will resume.”

The actions were seen as a signal to both nations not to interfere in Iraq’s affairs as American and Iraqi forces prepare for the crackdown on armed groups in the capital.

Syria is believed to be harboring 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 American officials have complained that Iran smuggles weapons to Shiite extremists who have killed Americans and provides Shiite militia with training and support.