BAGHDAD, June 17 (Xinhua) -- At least six Islamic State (IS) militants were killed Sunday in an airstrike on IS hideout in Iraq's central province of Salahudin, a paramilitary Hashd Shaabi source said.

The incident took place early in the morning when the Iraqi aircraft bombarded an IS hideout in Farhatiyah area near the town of Balad, some 80 km north of the Iraqi capital Baghdad, destroying the hideout and killing six IS militants inside, Sheikh Safaa al-Timimi, a leader of a brigade in Saraya al-Salam militia, told Xinhua.

The airstrike was based on intelligence reports by Saraya al-Salam, or Peace Companies, affiliated with the prominent Shiite cleric Moqtada al-Sadr, Timimi said.

Sadr's militia is a reformation of the previous militia Mahdi Army, which he led during the U.S. occupation of Iraq and the subsequent sectarian strife in the years after 2003.

Later in 2014, Sadr announced the formation of Peace Companies to protect Shiite shrines from the IS following the June 10, 2014 blitzkrieg when the group seized large swathes of territories in predominantly Sunni provinces in northern and western Iraq.

Key cities of Salahudin province, including the provincial capital Tikrit, some 170 km north of Baghdad, were captured by IS militants in June 2014, but the Iraqi security forces freed the province during major anti-IS offensives.