A member of Iraqi security forces gestures in the town of al-Alam March 9, 2015.[Photo/Agencies]

TIKRIT, Iraq - Iraqi security forces on Monday retook control of the town of al-Alam in Salahudin province after clashes with the Islamic State (IS) militants, as the troops continued their push toward the provincial capital city Tikrit, a security source said.

The troops and allied Shiite and Sunni militias, backed by armored vehicles and covered by Iraqi aircraft, entered the town just east of Tikrit from the south and the east after recapturing several outside villages, the source told Xinhua on condition of anonymity.

Sporadic clashes are still underway inside the town as the IS militants are still fighting in some small pockets on the western side of the town, the source said, adding that explosive experts had started defusing dozens of roadside bombs and booby-trapped buildings.

Meanwhile, the Iraqi forces started to clear roadside bombs on the roads leading to the outer neighborhoods of Tikrit city, as heavy clashes and shelling continued on IS positions inside the city, the source said.

Separately, the troops and allied Shiite militias arrived at Ajil oilfield east of Tikrit after days of clashes with the IS militants, the source said.

Earlier on Thursday, the IS militants apparently set fire to the oil installations as flames and plumes of black smoke rose above the area, the source added.