THULUYA, Iraq, 4 August 2003 — Two hours before the dawn call to prayer, in a village still shrouded in silence, Sabah Kerbul’s executioners arrived. His father carried an AK-47 assault rifle, as did his brother. And with barely a word spoken, they led the man accused by the village of working as an informer for the Americans behind a house girded with fig trees, vineyards and orange groves. His father raised his rifle and aimed it at his oldest son. “Sabah didn’t try to escape,” said Abdullah Ali, a village resident. “He knew he was facing his fate.” The story of what followed is based on interviews with Kerbul’s father, brother and five other villagers who said witnesses told them about the events. One shot tore through Kerbul’s leg, another his torso, the villagers said. He fell to the ground still breathing, they said, his blood soaking the parched dust near the banks of the Tigris River. His father could go no further, and according to some accounts, he collapsed. His other son then fired three times, the villagers said, at least once at his brother’s head. Kerbul, a tall, husky 28-year-old, died.

“It wasn’t an easy thing to kill him,” his brother Salah said. In his simple home of cement and cinder blocks, the father, Salem, nervously thumbed black prayer beads this week as he recalled a warning from village residents earlier this month. He insisted his son was not an informer, but he said his protests meant little to a village seething with anger. He recalled their threat was clear: Either he kill his son, or villagers would resort to tribal justice and kill the rest of his family in retaliation for Kerbul’s role in a US military operation in the village in June, in which four people were killed.

“I have the heart of a father, and he’s my son,” Salem said. “Even the Prophet Abraham didn’t have to kill his son.” He dragged on a cigarette. His eyes glimmered with the faint trace of tears. “There was no other choice,” he whispered.

In the simmering guerrilla war fought along the Tigris, US officials say they have received a deluge of tips from informants, the intelligence growing since US forces killed former president Saddam Hussein’s two sons last week. Acting on the intelligence, soldiers have uncovered surface-to-air missiles, 45,000 sticks of dynamite and caches of small arms and explosives. They have shut down safe houses that sheltered senior Baath Party operatives in the Sunni Muslim region north of Baghdad and ferreted out lieutenants and bodyguards of the fallen Iraqi president, who has eluded a relentless, four-month manhunt.

But a shadowy response has followed, a less-publicized but no less deadly theater of violence in the US occupation. US officials and residents say informers have been killed, shot and attacked with grenades. US officials say they have no numbers on deaths, but anecdotal evidence suggests that the campaign is widespread in a region long a source of support for Saddam’s government. The US officials declined to discuss specifics about individual informers and would not say whether Kerbul was one.

Lists of informers have circulated in at least two northern cities, and remnants of Saddam’s Fedayeen militia have vowed in videotaped warnings broadcast on Arab satellite networks that they will fight informers “before we fight the Americans.”

The surge of informants has provoked anger in towns along the Tigris. Some residents say informants are drawn to rewards from US field commanders of as little as $20 and as much as $2,500. The informants are occasionally interested in settling their own feuds and grudges with the help of soldiers, the residents said. Others contend that the informers are exploiting access to US officials to emerge as power brokers in the vacuum that has followed the fall of the government on April 9. “Time’s running out. Something will happen to them very soon,” said Maher Saab, 30, in the village of Saniya. The US military says bluntly it does not have the means to safeguard those providing intelligence. Residents of Thuluya said they had no doubt about Kerbul. After the operation in the village, dubbed Peninsula Strike, a force of 4,000 soldiers rounded up 400 residents and detained them at an air base seven miles north. An informer dressed in desert camouflage with a bag over his head had fingered at least 15 prisoners as they sat under a sweltering sun, their hands bound with plastic. Villagers said they soon recognized his yellow sandals and right thumb, which had been severed above the joint in an accident.

“We started yelling and shouting, ‘That’s Sabah! That’s Sabah!’” said Mohammed Abu Dhua, who was held at the base for seven days and whose brother died of a heart attack during the operation. “We asked his father, ‘Why is Sabah doing these things?’”

In the raid, three men and a 15-year-old boy were killed, all believed by villagers to have been innocent. Within days, many focused their ire on Kerbul, who had served a year in prison for impersonating a government official and was believed to have worked as an informer after he was released. Young children in the street sang a limerick about him: “Masked man, your face is the face of the devil.” Calls for revenge were heard in many conversations.

Kerbul’s family said US forces took him to Tikrit, then three weeks later, he went to stay with relatives across the Tigris in the village of Alim. As soon as word of his release spread, his brother Salah and uncle Suleiman went there to bring him back.

“We sent a message to his family,” said Ali, a retired colonel whose brother was among those killed during the operation. “You have to kill your son. If you don’t kill him, we will act against your family.”

His father appealed, Ali recalled, saying he needed permission from US forces. “We told him we’re not responsible for this,” Ali said. “We told him you must kill your son.” Kerbul’s body was buried hours after the shooting, his father said, carried to the cemetery in a white Toyota pickup.

Neither US military officials in Thuluya nor Tikrit said they were aware of the killing.