Iraqi government forces are continuing an offensive to retake the northern city of Tikrit from Sunni rebels.

Aircraft have struck at rebel positions and clashes have broken out in various parts of the city, witnesses and officials have said.

Troops had reportedly pulled back to the nearby town of Dijla as Saturday's initial offensive met stiff resistance.

The city of Tikrit was captured by Sunni rebels on 11 June as they swept across large parts of northern Iraq.

"The security forces are advancing from different areas", Lt-Gen Qassem Atta told journalists. "There are ongoing clashes."

There was fighting in the northern Qadissiyah district, near the university where troops established a foothold in the city a few days ago, witnesses told the Associated Press.

An unnamed official also told the agency of clashes around an air base formerly used by the US military, Camp Speicher.
Improvised devices

Heavy fighting took place on Saturday between the Iraqi security forces and armed men from different factions controlling Tikrit, resulting in many casualties on both sides, eyewitnesses and journalists told the BBC.

Insurgents, led by the Islamic State in Iraq and the Levant (Isis), were reported to have shot down a helicopter and captured the pilot.

The witnesses said the Iraqi forces had been hampered in their bid to retake Tikrit by the large number of improvised explosive devices laid on the approaches to the city.

But Lt-Gen Atta said that during Sunday's offensive many of the devices had been detonated.

Fear inside Tikrit

"We cannot live here another day. The entire night we have only heard bombs bursting all around the hospital" - Marina Jose, one of 46 stranded Indian nurses at a Tikrit teaching hospital, tells BBC

'No-one wants to stay here'

Meanwhile, Iraq said it had received the first batch of military jets ordered from Russia in order to help fight the militants.

The defence ministry said five Sukhoi aircraft would enter service in "three to four days".

Speaking to the BBC on Sunday, UK Foreign Secretary William Hague called for political unity in Iraq to help fight what he called the "mortal threat" to the state.

"Security operations will only work with strong political support from all elements in Iraq" he said.

Mr Hague's intervention will add to the pressure on Iraq's leaders to form a national unity government, correspondents say.

It follows a call from Iraq's most influential Shia cleric, Grand Ayatollah Sistani, for a prime minister to be appointed by Tuesday - when the new parliament meets - to try to defuse the political crisis.

Prime Minister Nouri Maliki wants a third term, though observers say he is seen by many as having precipitated the crisis through sectarian policies that have pushed Iraq's Sunni minority into the hands of Isis extremists.

BBC