17 Sunni insurgents and one US marine have lost their lives yesterday, during a house-to-house search in the town of Qusayba, near the border with Siria, Reuters informed.

According to the British press agency, the American and Iraqi forces, supported by tanks and air strikes, faced sporadic resistance groups formed by Sunni Arabs and foreign soldiers armed with Kalashnikov rifles and homemade bombs.

Operation Steel Curtain began on Saturday with the purpose to prevent the terrorist group al-Qaeda from smuggling into Iraq money, foreign soldiers and weapons.

Four other American soldiers died after a suicide bomber has detonated his car in a US checkpoint, south of Baghdad.

Al Qaeda's military wing in Iraq said that all those who have collaborated with the military or with the government will be targeted and gave the military 24 hours to stop the offensive.

"Their homes shall be destroyed on their heads after women and children leave", it is said in a statement posted on a Web site used by al Qaeda's Iraq leader, Abu Musab al-Zarqawi.