Iraqi security forces launched a major offensive on the northern city of Tikrit on Saturday. The military received backing by both manned and unmanned aircraft, according to Iraqi officials.

Two days ago, the Iraqi military air-dropped soldiers into the area to help regain control over major buildings, including the university. Some 30 Sunni militants have been killed since the latest offensive began, according to Iraqi military spokesperson Qassim Atta.

"Their morale has started to collapse," Atta said.

The US military advisers, recently deployed to Iraq, were aiding Iraq's military in the operation on Saturday, according to the military spokesperson, who said they were "studying important targets."

The Iraqi military drew toward Tikrit from its southern base in Samarra at the beginning of Friday, located roughly 60 kilometers (37 miles) down the road. The northern city is the administrative center of the Salah ad Din Governorate and the hometown of the late dictator Saddam Hussein.

A separate report indicated that 20 military personnel had also been killed in the clashes in the areas surrounding Baghdad in clashes with ISIS militants.

In a blitz operation in recent weeks the ISIS also captured Mosul, Iraq's second-largest city, along with a swath of northern and north-central Iraq.

Plea for unity government

On Friday, the country's top Shiite cleric, Grand Ayatollah Ali al-Sistani joined international calls for Iraqi Prime Minister Nuri al-Maliki to form a more ethnically-inclusive government. Many in Iraq's majority Shiite community have heeded the cleric's message to stop the Sunni insurgency before it splits the country further.

Al-Sistani urged politicians to agree on the next prime minister, parliament speaker and president by the time the new legislature meets on Tuesday, said a cleric who represents Sistani during a Friday sermon.

Maliki personally won the most votes in April elections, and his State of Law bloc won the most seats by far, but he failed to gain the majority needed to govern alone, which seems likely to lead to arduous coalition negotiations.

The swath of land now under ISIS control has raised fears that the al Qaeda splinter group may accomplish its goal of carving out an "Islamic emirate." The area would also include parts of Syria, where ISIS militants are seeking the ouster of Syrian President Bashar al-Assad.

kms/mz (AP, AFP, Reuters)