Iraqis embrace each other shortly after they were released from Abu Ghraib prison in Baghdad, June 7, 2006. [Reuters]

Almost 600 prisoners were released in Iraq on Wednesday, state television reported, a day after new Prime Minister Nuri al-Maliki said a total of 2,500 would be freed to help foster national reconciliation.

It was one of the biggest such releases of prisoners held in Iraqi or American detention since US-led forces invaded the country three years ago to topple Saddam Hussein.

"I spent 16 months in jail without any specific reason. They only questioned me once, accusing me of funding terrorism," said one of more than 100 people freed in Baghdad.

He said he had been arrested by Iraqi forces and then handed over to the US-run Abu Ghraib prison.

"I'm happy to return to my family," added Youssef Khidr, 38, looking exhausted.

Most of those in detention are believed held on suspicion of involvement in the insurgency.

The move by Maliki appeared to be an attempt to shore up his own authority at a time when rivalries within his ruling Shi'ite Alliance have cast doubt over his effectiveness.

State television, citing the Justice Ministry, said a total of 594 people had been freed across Iraq.

Many of those in detention -- estimated at more than 28,000 -- are from Saddam's once dominant Sunni community, which forms the backbone of an insurgency against the US-backed, Shi'ite-led government.

Maliki, who has pledged to heal sectarian wounds and crush the insurgency, said in a televised statement on Tuesday that the prisoner release would free those who had no clear evidence against them or had been detained mistakenly.

Initially, 500 people would be let out on Wednesday, he said, but did not give details. It was not immediately clear how many of them were in Iraqi or US custody.

Maliki had cited the release of those imprisoned without just cause as one of his priorities when his cabinet took office in May. Such detentions, by Iraqi and US security forces, have been a major source of popular discontent.

But "Saddam loyalists" or "terrorists" would not be freed.

A U.N. report last month said there were 28,700 detainees in Iraq, including 5,000 held by the Interior Ministry even though it should only detain people for short periods of time.

SHI'ITE POWER STRUGGLE

Maliki's prisoner release came at a time when his fractious, Shi'ite political Alliance is blocking his efforts to name new interior and defense ministers, who he hoped would lead his charge against insurgents and sectarian violence.

The two key security jobs were left vacant when the self-styled government of national unity took office on May 20 because of a failure to agree on names.

Maliki said this week he would present his candidates to the next session of parliament. The assembly's deputy speaker later said it would be held on Thursday.

Violence has continued to rage across Iraq since his grand coalition of majority Shi'ites and minority Sunnis and Kurds took office less than three weeks ago.

In Baghdad, thirteen out of some 50 Iraqi transport workers who were abducted earlier this week were found alive but some showed signs of torture, police sources said.

Police found them sitting on a street in central Baghdad around midnight local time on Tuesday, apparently dumped there. Some had been shot in the foot.

In another part of the capital, gunmen in a car shot dead four policemen and wounded another, police sources said.

TALIAN WITHDRAWAL

Visiting Italian Foreign Minister Massimo D'Alema said he believed his country's troops would return home from Iraq by the end of this year.

Prime Minister Romano Prodi, who took office last month, has vowed to live up to campaign promises for a swift pull-out of Italy's military presence of around 2,600 troops. He has called the Iraq war a "grave error."

"We think that by the end of this year the Italian military mission will end in Iraq," D'Alema said during a news conference with his Iraqi counterpart Hoshiyar Zebari, speaking through an Arabic translator.

(Additional reporting by Michael Georgy, Ahmed Rasheed and Mariam Karouny in Baghdad)