BAGHDAD (Reuters) - In a country ravaged by sectarian bloodshed, Sunni Abu Alaa believed contesting elections on a list with Shi'ites would promote unity.

Then his brother ended up like so many other Iraqis -- kidnapped and murdered. And he came to a conclusion shared by many other Sunnis whose relatives have been abducted and killed.

"I am 99 percent sure it was Shi'ite militiamen connected to the government," he said, looking over photographs of his brother Abu Akeel's corpse in the morgue.

"They tortured him and put a bullet in his head."

As U.S. and Iraqi officials speak of how Iraqi forces have improved after training, Sunnis are focused on what they say are widespread abuses at the hands of Shi'ite government forces.

Abu Alaa's ordeal began two weeks ago -- about the time that U.S. troops discovered 170 Sunni prisoners locked in an Interior Ministry bunker, some of whom appeared to have been tortured.

Gunmen shot a Shi'ite friend and Abu Akeel rushed him to hospital, where the friend later died.

Shortly afterwards, armed men in civilian clothes with walkie talkies showed up at the ward and took Abu Akeel and three Shi'ites to a room for questioning, said Abu Alaa.

The three Shi'ites were eventually released. Abu Alaa said one of them told him he had been blindfolded and taken to a building where he could hear people being tortured.

DEATH AFTER RANSOM PAID

There was no word on his brother for a couple of days until a man called saying he had been kidnapped and demanded ransom. They negotiated a price. The kidnappers took the money but killed him anyway.

"They said my brother would be delivered one day later. That's when we searched the morgues," said Abu Alaa, who asked that his full name not be used for fear of reprisals.

"They drilled his face. One of his eyes is missing. Part of his head was crushed, probably by a vice. He took a Shi'ite friend to the hospital and this is what happened to him."

Iraq's Shi'ite-led government has said it hopes December 15 elections will encourage Sunni insurgents to lay down their weapons and join peaceful politics.

But mounting Sunni accusations that government forces are kidnapping and executing Sunnis have fueled fears of civil war.

In a damning indictment, former prime minister Iyad Allawi accused the government of condoning abuses equal to atrocities committed under Saddam.

The U.S.-backed Iraqi government, which promised to deliver human rights after decades of iron-fisted rule under Saddam Hussein, has denied the accusations.

The government says it investigates any reports of abuses in its war against guerrillas, who have killed thousands of security forces and civilians with suicide bombings and shootings.

But those pledges do not ease sectarian tensions that spread after each killing.

Abu Alaa still plans to take part in the elections for Iraq's first postwar full-term government with Shi'ite running mates.

But his mind was elsewhere as he sat with Abu Akeel's son looking over the photographs showing puncture wounds on the face and eye of his brother's corpse and welts covering the back of the former taxi driver.

"We will get revenge. We still don't know exactly who did this but the hospital staff let his killers in and that's where we are going to start," he said.