US forces arrested on Tuesday the deputy head of Iraq's interim parliament and a high-ranking member of a Sunni political party after a dawn raid on his Baghdad home, spokesman from his party said.

Naseer Ayaef, a senior member of the Iraqi Islamic Party, was arrested in his home in the western Jamiah neighborhood despite he enjoys immunity as the deputy speaker of the national council (parliament), said the spokesman Iyad al-Samarrai.

Al-Samarrai appealed to Prime Minister Iyad Allawi and national council president Fouad Maasum to intervene.

The arrest was linked to pressures exerted on the Iraqi Islamic Party because of its opposition to the military offensive against Fallujah, stressed the spokesman.

Last week, the Iraqi Islamic Party withdrew from the interim government in protest over the US-Iraqi full-scale assault on Fallujah.

"The Iraqi Islamic Party has decided to withdraw from the government in protest against the attack on Fallujah that causing the killing of civilians," announced Mohsen Abdul Hamid, the secretary of the party and member of Iraq's provisional National Assembly.

Since last Monday, the US military and interim Iraqi government troops have launched full-scale assault on Fallujah, 50 km west of Baghdad, in order to retake the key rebel stronghold to pave way for the general elections slated for January.