BAGHDAD A bomb-rigged truck exploded at a checkpoint Tuesday near the western city of Ramadi, killing two U.S. Marines and wounding three others in an apparent strike by al-Qaida in Iraq in one of its former strongholds.
At least one civilian also died, and two dozen were injured in the blast, the latest in a string of recent strikes in areas where local Sunnis have joined U.S. forces to battle al-Qaida.
Ramadi is the capital of Anbar province, which was once held by insurgents. But it has been relatively peaceful since local Sunni tribal leaders joined forces with the U.S. military against the terror movement.
Iraqi police said the suicide attacker drove a small water tanker packed with explosives to the checkpoint and detonated them when he reached the guards. The U.S. military said two Marines were killed and three injured.
In Diyala province, north of Baghdad, a woman detonated an explosive vest at the entrance to an Iraqi police station in Jalawla, killing eight policemen and a Kurdish security guard, police said. Ten other people were wounded.
It was the second suicide attack by a woman in as many days in Diyala, which has been a flashpoint in the battle against al-Qaida. A young woman blew herself up Monday at the headquarters of a group of U.S.-allied Sunni fighters, killing three people and wounding three others, the U.S. military said.
Al-Qaida has been regrouping after suffering a devastating blow last year when thousands of Sunni tribesmen turned against them. Last weekend, al-Qaida announced a one-month offensive against U.S. troops and Sunnis who have joined forces with Americans.
Osama bin Laden's deputy, Ayman al-Zawahri, said in an audiotape posted Tuesday on the Internet that al-Qaida-led insurgents in Iraq were the "primary force" in battling the Americans and "challenging Iranian ambitions" in this country.
The renewed activity by al-Qaida has occurred while attention has focused on the Iraqi government crackdown against Shiite militias, chiefly the Mahdi Army of anti-American cleric Muqtada al-Sadr.
Last month, Prime Minister Nouri al-Maliki, a Shiite, launched an offensive against Shiite militias in the southern city of Basra. The fighting quickly spread to Sadr City, the Mahdi Army's Baghdad stronghold, where militants fired rockets at the U.S.-protected Green Zone.
In the latest fighting, two Shiite extremists were killed in Sadr City, the U.S. military said.
At least eight civilians also were killed and 15 wounded in the district in a rocket strike, Iraqi police said. The U.S. military said an American helicopter fired a missile at extremists transporting rockets at the same hour but insisted no civilians were in the area.
Also Tuesday, the U.S. command announced that an American Marine was killed and another wounded the day before when a roadside bomb struck a U.S. convoy in Basra.
U.S. and British forces have been assisting Iraqi forces in Basra since their offensive bogged down due to poor planning, widespread desertions and fierce resistance by the militias.
The Iraqi army command in Basra declared the city and the surrounding province under government control Tuesday and gave top Mahdi commanders in the area 24 hours to surrender.
Also in Basra, a senior aide to Iraq's top Shiite cleric Grand Ayatollah Ali al-Sistani died Tuesday, a week after being seriously wounded in an assassination attempt. Two other al-Sistani representatives were injured in separate ambushes.
The attacks came days after a top aide of al-Sadr was killed in Najaf part of the ongoing Shiite power struggle.
The crackdown had led to fears that al-Sadr, who is believed to be in Iran, may declare full-scale war on the U.S.-backed government.
On Monday, top Sadrists warned that open warfare was a "strong possibility" and complained that the government appeared uninterested in a peaceful settlement.