MOSUL, Iraq (AP) — The Latest on the battle to retake Mosul from the Islamic State group (all times local):

12 p.m.

A provincial spokesman says a suicide attack against Shiite pilgrims north of Baghdad has killed at least 11 people.

The spokesman for Salahuddin province, Ali al-Hamdani, says Sunday's attack took place in the city of Samarra, 60 miles (95 kilometers) north of Baghdad, where a revered Shiite shrine is located.

Al-Hamdani said the bomber parked his explosives-laden ambulance in a parking lot and walked up to the pilgrims who had just left their busses and were heading to the shrine about 500 meters away. He first detonated the car and then blew up himself.

He added that at least four Iranians were among the dead. Up to 100 others were wounded, he said.

No group has claimed responsibility for the attacks, but Islamic State militants have claimed multiple similar attacks.

10: 45 a.m.

A provincial spokesman says a suicide attack against a security checkpoint north of Baghdad has killed at least nine people.

The spokesman for Salahuddin province, Ali al-Hamdani, says the suicide bomber rammed his explosives-laden car during rush hour Sunday morning into the main checkpoint at the southern entrance of the provincial capital, Tikrit.

Al-Hamdani said five female students, a woman and three policemen were killed. He added that 25 other people were wounded.

No group has claimed responsibility for the attacks, but Islamic State militants have claimed multiple similar attacks. The Sunni extremists frequently launch attacks targeting Iraq's security forces and civilians in public areas.

In April 2015, Iraqi security forces drove out IS militants from Tikrit, about 80 miles (130 kilometers) north of Baghdad.

9 a.m.

Iraq's special forces say they are still struggling to clear neighborhoods retaken from the Islamic State group along Mosul's eastern edge.

Lt. Col. Muhanad al-Timimi says Sunday that elaborate defenses built by IS and the presence of civilians have slowed progress.

The civilians make it more difficult for Iraqi commanders on the ground to get requests for U.S.-led coalition air strikes cleared. Iraq's special forces are some of the country's best troops, but they largely rely on air support.

Iraqi forces first entered the eastern edge of Mosul on Tuesday. On Friday, forces began pushing into Mosul proper, but so far have only advanced into the city just over a kilometer (mile). On the city's southern front Iraqi forces are still some 20 kilometers from the city center.