BAGHDAD — United States Secretary of State John Kerry warned Middle East nations yesterday against taking new military action in Iraq that might heighten already-tense sectarian divisions, as reports surfaced that Syria had launched air strikes across the border and Iran has been flying surveillance drones over the neighbouring country.

A senior Iraqi military official confirmed that Syrian warplanes bombed militants’ positions on Tuesday in and near the border crossing in the town of Qaim. He said Iraq’s other neighbours — Jordan, Kuwait, Saudi Arabia and Turkey — were all bolstering flights just inside their airspace to monitor the situation. The official spoke on condition of anonymity because he was not authorised to speak to the media.

US officials said the strikes appeared to be the work of Syrian President Bashar Assad’s government. They said the target was the Islamic State of Iraq and Syria (ISIS), a Sunni extremist group that seeks to carve out a purist Islamic enclave across both sides of the Syria-Iraq border.

“We’ve made it clear to everyone in the region that we don’t need anything to take place that might exacerbate those sectarian divisions that are already at a heightened level of tension,” Mr Kerry said at a meeting of diplomats from North Atlantic Treaty Organization nations.

“It’s important that nothing take place that contributes to the extremism or could act as a flash point with respect to the sectarian divide.”

He said Baghdad needs to take steps to ensure Iraq’s military can defend the country without relying on outside forces. The US is sending 300 military advisers.

Nevertheless, the involvement of Syria and Iran in Iraq suggests a developing Shia axis among the three governments in response to the raging Sunni insurgency. In an unusual twist, the US, Iran and Syria now find themselves with overlapping interests in stabilising Iraq’s government.

Iraqi Prime Minister Nouri Maliki yesterday rejected calls for an interim “national salvation government” in his first public statement since US President Barack Obama challenged him last week to create a more inclusive leadership or risk a sectarian civil war.

Several politicians, including Mr Ayad Allawi, a secular Shia who has been named as a possible contender to replace Mr Maliki, have called on him to step down and form an interim government that could provide leadership until a more permanent solution can be found. Mr Maliki, however, insisted the political process must be allowed to proceed following recent national elections in which his bloc won the largest share of Parliament seats.

Qaim, where the Syrian air strikes took place, is located in the vast and mostly Sunni Anbar province. Its provincial government spokesman, Mr Dhari Rishawi, told the Associated Press on Tuesday that 17 people were killed in an air raid there.

Yesterday, militants overran the Ajeel oil site, 30km east of Tikrit, which contains at least three small oilfields that produce 28,000 barrels per day, an engineer working at the field said, adding that the nearby town of Al Alam was seized by militants.

Militants including ISIS and allied Sunni tribes also battled Iraqi forces in the town of Yathrib, 90km north of Baghdad, yesterday, witnesses said. Four militants were killed, they said. Insurgents have surrounded a massive air base nearby and struck it with mortars. Agencies