Members of ISIS terrorist group on Monday carried out two simultaneous attacks on the areas to the east and north of Tikrit, 170 km north of Baghdad.

According to a security source from the Salahuddin province, where the attacks were carried out, the ISIS militants launched an attack on Sunday evening against Ajil oil field located in north east of Tikrit city. The militants, he said, carried out another attack on al-Mubaddad area, in east of the city.

“The attack began with artillery fire followed by a ground attack on Iraqi troops' positions on two frontlines and fierce clashes between the two sides are ongoing with the militants advancing in some areas,” the source said.

The Iraqi forces have urged military helicopters to intervene in order to prevent the militants from advancing and to bring the situation under control, the source added.

ISIS captured Mosul in 2014, when it began its terrorist campaign against Iraq. The terrorist group then named the city as its so-called headquarters.

ISIS has also been accused of using chemical weapons in Iraq as well as in neighboring Syria.

According to UN human rights spokeswoman Ravina Shamdasani, ISIS was stockpiling ammonia and sulfur agents in Mosul possibly for use as chemical weapons.