BAGHDAD, 12 March 2008 — Forty-six people were killed in violence across Iraq yesterday, including 14 mourners from one family when a roadside bomb hit a bus in a southern province, security officials said.

In the southern city of Kut, members of Shiite cleric Moqtada Sadr’s Mehdi Army fought Iraqi security forces in clashes that left 14 people dead, security officials said. Sadr said last month he had renewed a cease-fire. Violence has fallen across Iraq by 60 percent since last June, but yesterday’s attacks underlined how fragile the security gains are.

Police at the general hospital in Nassiriya, 375 km (235 miles) south of Baghdad, said the casualties from the roadside bomb included women and children. Survivors said the bomb appeared to target a passing US military convoy.

Police said the bus was carrying members of a family returning from mourning rites for a dead relative in the city of Najaf when it was hit about 60 km (40 miles) south of Nassiriya.

“There was blood and human flesh in the bus and on the floor. Shoes of men, women and children were everywhere,” bus driver Zaji Abdul Hussein said afterward.

Rahman Shaker, 60, covered in blood after carrying his badly wounded wife from the wreckage, said a US convoy had just passed on the other side of the road when the bomb went off.

In Kut, 170 km (105 miles) southeast of Baghdad, an apparent attempt to arrest a Mehdi Army leader sparked clashes between the militia and the Iraqi security forces in two districts. There were conflicting reports that US troops were involved.

The commander of a quick reaction force in Kut, Lt. Col. Majid Al-Amara, said 14 people had been killed, including four militiamen, three children and a policeman, and 28 wounded.

Much of the fighting was reported to have died down by night-fall although sporadic shooting could still be heard.

In separate clashes north of the capital, police said four Iraqi policemen, four gunmen and a civilian were killed in an attack on a security checkpoint in Mosul.

In Dhuluiya, also north of Baghdad, a suicide car bomber killed five people, including three members of a neighborhood security unit, and wounded 14 in an attack on a checkpoint, police Lt. Col. Ibrahim Al-Jubouri said.

Earlier yesterday, the US military said a roadside bomb had killed three US soldiers and an interpreter in Diyala province northeast of Baghdad on Monday, the same day a suicide bomber killed five US soldiers in the capital.

In Samarra, 100 km (60 miles) north of Baghdad, a mass grave containing 20 decomposed bodies, including six women and five children, was found, police said. Police blamed Al-Qaeda for the deaths.