Baghdad - Iraqi forces pressed a counter-attack on Saddam Hussein's hometown Tikrit on Sunday as Russia delivered warplanes to aid Baghdad in a crisis said to rival the country's brutal sectarian war.
Government planes pounded Tikrit and clashes raged across the city as thousands of troops advanced in Iraq's most ambitious operation since insurgents led by the jihadist Islamic State of Iraq and the Levant (ISIL) overran swathes of five provinces this month.
Alarmed world leaders have meanwhile urged a speeding up of government formation following April elections, warning the conflict driven by sectarian divides cannot be resolved militarily.
And while beleaguered Prime Minister Nuri al-Maliki has conceded a political solution is necessary to end the crisis, his security spokesperson has for days touted successes in the Tikrit operation that could be crucial not only tactically, but also for morale in the security forces.
"The security forces are advancing from different areas" around Tikrit, Lieutenant General Qassem Atta told reporters. "There are ongoing clashes."
Atta said troops had detonated bombs planted along routes into the city, which fell to militants more than two weeks ago.
Witnesses in the city itself reported waves of government air strikes in various areas of central Tikrit and Saddam's palace compound in the city.
The Iraqi forces, according to Atta, are coordinating with recently-arrived US military advisers in "studying important targets"Worse than sectarian war
Maliki's national reconciliation adviser, Amr Khuzaie, told AFP the crisis is even more dangerous than a brutal period of Sunni-Shi'ite sectarian violence that peaked in 2006-2007 and killed tens of thousands.
"Now, the danger is definitely more... than 2006, 2007," Khuzaie said.
Before, militant groups sparked a "sectarian war, but now [the] war is more organised" and the abilities of the militants are greater, he said.
Also Sunday, fighters backed by the Kurdish peshmerga force advanced on the Shi'ite-majority village of Basheer, south of Kirkuk, which was taken over by militants during the offensive, officials said.
It comes as Iraq took delivery of the first batch of Sukhoi warplanes from Russia, with the newly-purchased Su-25s expected to be pressed into service as soon as possible.
An Iraqi official said pilots from Saddam's air force would fly the planes.
Su-25s are designed for ground attack, meaning they would be useful for Iraqi forces trying to root out ISIL-led militants from a string of towns and cities they have seized.$500m Sukhoi deal
Maliki on Thursday announced Baghdad was buying more than a dozen Sukhoi aircraft from Russia in a deal that could be worth up to $500m.
Washington, which has pushed for political reconciliation in the face of what Secretary of State John Kerry has described as an "existential" threat, has sent military advisers to help Iraqi commanders but has so far not acceded to Baghdad's appeal for US air strikes.
The US has stopped short of calling for Maliki to quit but has left little doubt it feels he has squandered the opportunity to rebuild Iraq since American troops withdrew in late 2011.
American officials have also said a proposed $500m plan to arm and train moderate rebels in neighbouring Syria could also help Iraq fight ISIL, which operates in both countries.Hundreds of soldiers killed
Maliki's security spokesman has said hundreds of soldiers have been killed since the insurgent offensive was launched on 9 June, while the UN puts the overall death toll at over 1 000, mostly civilians.
International organisations have urged the establishment of humanitarian corridors to provide aid amid the fighting, with 1.2 million people having been displaced by unrest this year in Iraq.
World leaders have insisted on a political settlement among Iraq's various communities and Grand Ayatollah Ali al-Sistani, revered among the country's Shi'ite majority, has urged political leaders to quickly form a government after parliament convenes on Tuesday.
Maliki has acknowledged that political measures are necessary, but politicians have nevertheless cautioned that naming a new cabinet could still take a month or more.
Despite unity calls, Iraqi Kurdish leader Massud Barzani has said Baghdad could no longer object to Kurdish self-rule in Kirkuk and other areas from which federal forces withdrew as the insurgents advanced.
Kurdish forces moved into areas vacated by Iraqi federal soldiers, putting them in control of disputed areas that they have long wanted to incorporate into their three-province autonomous region, a move Baghdad strongly opposes.
Khuzaie had harsh words for the Kurds' actions, saying they "acted as ISIL acts [because] they want to obtain the disputed areas".