BAGHDAD - A roadside bomb exploded near a minibus full of Shiite civilians on Saturday, killing at least three people and wounding nine as they went to visit relatives south of Baghdad, police said.
U.S.-led forces raided houses in search of Shiite extremists elsewhere in the volatile area.
The minibus was travelling the main highway from Baghdad to the predominantly Shiite southern city of Hillah when it was struck by the explosion around 6:30 a.m. in Iskandariyah, 50 kilometres from the capital.
There have been frequent attacks along sections of the highway in the mainly Sunni southern belts of Baghdad, although violence has recently dipped as local Sunni tribal leaders joined forces with U.S.-led forces against "al Qaeda in Iraq."
Iraqi police said 30 suspected fighters from the Mahdi Army militia of radical Shiite cleric Muqtada al-Sadr were rounded up by joint U.S.-Iraqi forces during house-to-house searches in two eastern neighbourhoods in Diwaniyah, 130 kilometres south of Baghdad, early Saturday.
Violence against U.S.-led and Iraqi forces in the area around Diwaniyah has spiked recently as rival Shiite factions battle for power in the oil-rich area.
In eastern Diwaniyah, U.S.-led ground forces backed by two Polish helicopters came under fire from machine-guns and an anti-tank grenade launcher on Friday, the military said.
No coalition casualties were reported, but two militants were killed, according to a statement. It said the helicopters were called in after the ground forces were attacked with three roadside bombs and small-arms fire.
The governor of the Qadisiyah province, which includes Diwaniyah, met with Prime Minister Nouri al-Maliki in Baghdad on Saturday to ask for help boosting security in the region.
Gov. Hamid al-Khudhari dismissed concerns of rising tensions between al-Sadr's group and his party, the Supreme Islamic Iraqi Council. Al-Khudari replaced Gov. Mohammad al-Hassani, who was assassinated by a powerful roadside bomb in August.
"There have been outlawed armed groups trying to take control of the province for a long time,'' he said at a news conference after the meeting. "They are only criminals and we do not believe that there is political party that backs them.''
"We do have problems in the local security forces that make it difficult to ensure security and we asked the prime minister to fill the gaps in this regard,'' he said without elaborating.
Police also clashed with gunmen in the Shiite holy city of Karbala, 80 kilometres south of Baghdad, during a raid in which they detained a Sadrist leader, local authorities said without identifying the suspect.
In Baghdad, a bomb hidden in a trash can exploded in eastern Baghdad, killing a street sweeper and wounding three other people, police said.
The attacks occurred as Iraqis faced the threat of a new front opening with Turkey's threatened incursion into northern Iraq.
A Kurdish rebel leader, Murat Karayilan, threatened to strike an oil pipeline running into Turkey if the Turkish military targets bases of the separatist Kurdistan Workers' Party, or PKK, in northern Iraq.
"When Turkey starts a military operation against our bases, we will defend ourselves by targeting economic sites and one of our options is to hit the oil pipeline going from Kurdistan to Turkey because of the great economic value of this pipeline to Turkey and its army,'' Karayilan said.
The most senior leader in Iraq's Kurdish region, Massoud Barzani, appeared to raise the stakes in the standoff on Friday, warning Turkey that the region would defend itself against any cross-border military strike on rebel bases.
The tough line taken by the Kurds has stoked worries that a Turkish incursion could ignite a wider cycle of conflict and unrest in one of the few stable corners of Iraq.
Barzani said urgent talks were needed on all sides. But Turkey has flatly declared it is out of patience with escalating attacks by separatist guerrillas who use hideouts in northern Iraq.
As both Baghdad and Washington struggled to avert conflict between two of its key allies in the region, Turkey's prime minister insisted that the camps of Kurdish rebels in northern Iraq must be destroyed and rebel leaders extradited to Turkey for trial.
The PKK has battled for more than two decades for autonomy in Turkey's mostly Kurdish southeast. The conflict has claimed more than 30,000 lives.
Turkey's parliament on Wednesday gave the government a one-year window in which to launch cross-border offensives against Turkish Kurd rebel strongholds in Iraq. The vote led to large-scale protests by Iraqi Kurds, calls for restraint by Baghdad and Washington and uncertainty over Turkey's next move, which has helped push oil prices to record highs.
