BAGHDAD, Iraq (AP) – A mortar attack killed 10 civilians, mostly women and children, in a Shiite neighborhood in a Sunni-dominated town south of Baghdad on Monday, while at least four people were killed in the capital as a car bomb hit a bus carrying Shiites to a shrine, police said.

The attacks came one day before the culmination of Ashoura, the holiest day in the Shiite calendar commemorating the 7th century death of Imam Hussein, when huge public processions are expected in Karbala and other Shiite cities.

Meanwhile, a provincial government spokesman said Monday some 300 militants were killed in Sunday fighting in Najaf, when U.S.-backed Iraqi troops attacked insurgents allegedly plotting to kill pilgrims at an Ashoura festival.

Ahmed Deaibil, a spokesman for Najaf province, said the fighting had stopped but U.S. and Iraqi forces still had the area surrounded and had seized heavy machine guns, ammunition and other weapons.

He said 300 militants had been killed and 13 arrested, while the casualty toll for Iraqi forces was three soldiers and two policemen killed and 30 wounded. Iraqi security officials said earlier that one Sudanese was among the fighters captured.

In the Monday mortar attack, rounds rained down on the neighborhood in Jurf al-Sakhar, 43 miles south of Baghdad, in the morning, police spokesman Capt. Muthanna Khalid said. He said the 10 killed included three children and four women, and that five other people were wounded.

The attack came a day after mortar shells hit the courtyard of a girls’ school in a mostly Sunni Arab neighborhood of Baghdad, killing five pupils and wounding 20. U.N. officials deplored the attack, calling the apparent targeting of children “an unforgivable crime.”

In northern Baghdad, the parked car bomb struck the bus carrying Shiites to a holy shrine as the pilgrims were boarding the bus Monday. They were heading to Kazimiyah, which is home to the most important Shiite mosque in the capital.

Six other people were wounded, including a traffic cop, police said.

Elsewhere in the capital, a bomb hidden under a concrete barrier exploded as workers were paving a street in an intersection in a predominantly Shiite area in eastern Baghdad, killing one worker and wounding two others, police said.