Iraq's President Jalal Talabani said Saturday that the country's Sunni vice president, who stands accused of running a death squad, would stand trial only if promises were made regarding its fairness.

His remarks come with the country mired in a political row, with an arrest warrant out for Vice President Tareq al-Hashemi, and Shiite Prime Minister Nuri al-Maliki calling for the sacking of his Sunni deputy after the latter called him a dictator "worse than Saddam Hussein."

Iraqiya, the mostly Sunni-backed political bloc of Hashemi and deputy premier Saleh al-Mutlak, has boycotted parliament and the cabinet in protest at Maliki's alleged centralisation of power.

"Mr Tareq al-Hashemi is in the hospitality of the president of the republic," a statement from Talabani's office said.

"Hashemi will appear in front of justice at any time and anywhere in the country where there will be reassurances regarding the processes of justice, investigation and trial."

The statement did not specify what specific reassurances would be required.

Iraq's political crisis, coupled with a spate of attacks on Thursday in Baghdad which killed 60 people, has heightened sectarian tensions in the country less than a week after US troops completed their withdrawal.

Hashemi, who has disputed the charges, meanwhile, blamed collusion within the government and security forces for Thursday's violence, the deadliest in more than four months.

"This style of terrorist attack, it's well beyond even Al-Qaeda to do it," he told the BBC's Persian Service in comments published on Saturday.

"What has been done is well-organised, the people who plant all these explosives. They went freely, without any obstacles, regardless of many checkpoints that we do have, and simultaneously all these car bombs and explosives went off in one time."

He continued: "Those who were behind all these explosions and incidents (were a) part in the security of the government. I'm sure about that."

On Friday, Hashemi blamed Maliki for starting "a national crisis, and it's not easy to control," and likened the premier's behaviour to that of now-executed dictator Saddam Hussein.

Maliki convened a meeting of his crisis-response cell on Saturday, a statement from his office said, in which he admitted Iraq's security forces must examine whether "there are members in these forces cooperating with terrorist groups."

Turkish Foreign Minister Ahmed Davutoglu, meanwhile, said Hashemi should stay in Iraq, but noted Ankara would not turn him away if he requested asylum.

"What would be appropriate for us is that Mr Hashemi should stay within the Iraqi territory," he said in remarks broadcast by the state-run Turkish Radio and Television.

Davutoglu said the gravity of the allegation faced by Hashemi could not be minimised, and "must be clarified as soon as possible."

Earlier on Saturday, anti-US Shiite cleric Moqtada al-Sadr launched an "honour convention" which called for national unity and peace in Iraq following the US withdrawal.

The pact was signed by numerous lawmakers, academics and tribal leaders.