BAGHDAD, Oct. 1 (Xinhuanet) -- United States forces launched a major offensive against insurgents in the northern Iraqi city of Samarra early on Friday after three car bombings rocked Baghdad on Thursday.

    The US military has said that with the help of Iraqi forces it will retake rebel strongholds such as Samarra, Fallujah Ramadi and the Baghdad neighborhoods of Sadr City and Haifa Street by the end of the year so that elections can go ahead in January.

    All that came after insurgents detonated three car bombs near aUS military convoy in southern Baghdad on Thursday, killing at least 49 people and wounding nearly 200, many of them children. Ten US soldiers were among the wounded.

    It was the largest number of children killed in any single insurgent attack since the conflict erupted 17 months ago.

    The three bombs exploded at a neighborhood celebration as suicide bombers and other attackers struck in quick succession in three separate areas of the capital.

    Earlier, a suicide attacker exploded a car bomb in front of a government complex on the western outskirts of Baghdad, killing atleast one US soldier and two Iraqi policemen and wounding 60 people.

    The morning attack targeted a compound in the Abu Ghraib area housing the mayor's office, a police station and other buildings. US forces were guarding the complex.

    Also on Baghdad's outskirts, insurgents fired a rocket Thursdayat a logistical support area for coalition forces, killing one soldier and wounding seven, the military said in a statement.

    The Baghdad attacks came after the United States struck a suspected militant safe house in the rebel-held city of Fallujah.

     The Fallujah strike on Thursday was only the latest to target the city, which has been a "no-go" area for US troops. American ground forces have not entered Fallujah since the end of a three-week siege of the city in April that left hundreds dead.

    American jets, tanks and artillery units have repeatedly targeted Fallujah in recent weeks as US-led forces seek to assert control over insurgent enclaves ahead of elections slated for January.

    The military says the attacks have inflicted significant damageto a local rebel network, which has claimed responsibility for a series of bombings, kidnappings and other attacks.

    In the northern city of Talafar, a car bomb targeting the police chief killed at least four people and injured 19, includingfive policemen.

    In another northern city, Kirkuk, the mayor's chief bodyguard was gunned down in his vehicle which was then driven away by the attackers.

    In recent days, more than 140 foreigners have been kidnapped inIraq and at least 26 have been killed. Some were seized by insurgents as leverage in their campaign against the United Statesand its allies, others by criminals seeking ransom. Enditem