BAGHDAD, June 6 (Xinhuanet) -- Attacks on Iraqi police and security forces continued on Sunday as less than four weeks remained in the expected process toward the formal handover of sovereignty to an interim Iraqi government.

   A car bomb blew up at the gate of an Iraqi security force base just north of Baghdad midday Sunday, killing six Iraqis and wounding at least 20, said a US military officer at the scene.

   The blast targeted a training base for the Iraqi Civil Defence Corps at the Taji airbase, which used to be used by the former Iraqi army.

   According to a statement released on the Internet, a group ledby Al-Qaeda linked operative Abu Mussab al-Zarqawi claimed responsibility for the suicide attack in Taji.

   A squad affiliated to the Tawhid wa al-Jihad (Unification and Holy War) group attacked "the strongholds of the Americans andtheir apostate allies," said the statement.

   It mentioned two simultaneous assaults, one at "a camp for USforces in Taji" and the other at "a stronghold of the army andpolice loyal to the Americans" a few meters away from the former target.

   On Saturday, the same group announced on a website that itsarmed wing burned two vehicles and killed eight "CIA agents" on theroad to the Baghdad International Airport earlier in the day.

   Reports later revealed that two Poles and two US civilians, working as security contractors with the US-led coalition authority were killed in the incident.

   Also on Sunday, anti-occupation fighters attacked a police station south of Baghdad, killing 13 Iraqis and wounding ten others.

   The attackers, who disguised themselves as police, entered the building in the town of Musayyab and killed the victims before they blew up the building and fled the scene.

   Near the northern oil city of Kirkuk, an Iraqi policeman and acivilian were killed and nine other officers were wounded, five of them seriously, police said.

   The bomb exploded in Tuz Khurmatu, 75 km south of Kirkuk, as apolice convoy passed a checkpoint on a road frequently used by US troops, said the Qatar-based al-Jazeera TV channel.

   The road is regularly used by US troops travelling between Kirkuk and Tikrit, where the 1st Infantry Division has its headquarters.

   Northwest of Baghdad, a civilian contract driver was killed and a US soldier was wounded in a roadside bomb attack on a US military convoy, the US military said in a statement.

   According to the statement, the wounded soldier was from the 13th Corps Support Command. It did not give the nationality of the civilian driver who was killed in the attack which took place in Haditha, some 200 km northwest of Baghdad.

   The surge in the deadly attacks on Iraqis and foreigners, accused of cooperating with occupying troops, has been witnessed after the new government was established to take over power on June30.

   The 33-member cabinet was led by the CIA-favored Shiite leader Iyad Allawi, who had called for national restraint among resistance and vowed to crack down on "terrorists."   Enditem