US warplanes bomb Islamic State group in Iraq

(Al Jazeera)- The US military has conducted air strikes against Islamic State fighters near the northern Iraqi city of Erbil, the US Defence Department has said.

A Pentagon statement said two F/A-18 warplanes dropped 225 kilograms of laser-guided bombs on a mobile artillery piece which "[the Islamic State] was using ... to shell Kurdish forces defending Erbil where US personnel are located."

Later on Friday, the US military said it had conducted two additional air strikes to help defend the city where US personnel are assisting the government of Iraq.

"A remotely piloted aircraft struck a terrorist mortar position. When Islamic State fighters returned to the site moments later, the terrorists were attacked again and successfully eliminated," the Pentagon said.

According to the statement, in the third attack, four F/A-18 aircraft successfully struck a stationary Islamic State convoy of seven vehicles and a mortar position near Erbil.

"The aircraft executed two planned passes. On both runs, each aircraft dropped one laser-guided bomb making a total of eight bombs dropped on target neutralising the mortar and convoy," the Pentagon said.

Al Jazeera’s Jane Arraf, reporting from Erbil, said: "Fighters have captured US-made weapons as Kurdish troops withdrew from various regions. Washington also wants to address that."

US President Barack Obama had on Thursday authorised air strikes against Islamic State fighters in Iraq, who have taken over large areas of the country, saying the measure was meant to avert "genocide".

"We can act, carefully and responsibly to prevent a potential act of genocide," Obama said on Thursday, referring to the Yazidis, a religious minority group besieged by fighters from the Islamic State.

Several thousand Yazidis, members of an ancient pre-Muslim religious minority, are stranded on high ground in the north after being driven out of their home town of Sinjar by Islamic State fighters.

"I therefore authorised targeted air strikes if necessary to help forces in Iraq as they fight to break the siege and protect the civilians trapped there," he said.

Cleric calls for unity

The Islamic State, which is also active in Syria, has been advancing in various parts of Iraq, fighting against troops from the Kurdish and central governments.

The group sees Iraq's Shia Muslims and minorities such as Christians and Yazidis as infidels.

A senior US defence official on Thursday confirmed the mission had already dropped "critical meals and water for thousands of Iraqi citizens," referring to Yazidis trapped in the open on Mount Sinjar in northern Iraq.

Meanwhile, Iraq's senior Shia cleric Ayatollah Ali Sistani has called on Iraqis to unite to confront the threat from the Islamic State.

"All Iraqis should unify ranks and intensify efforts in the face of this big danger that threatens their present and future," said Sistani.

In what will be interpreted as a criticism of the Prime Minister Nouri al-Maliki, he also said those clinging to their positions were making a grave mistake.

The US air strikes and humanitarian air drops reflect the deepest engagement by Washington in Iraq since US troops withdrew in late 2011, after nearly a decade of war.