LONDON, OCT. 3 -- Iraq's security forces have tortured and executed dozens of Kuwaitis, including boys as young as 15, in an attempt to crush resistance after Saddam Hussein's army occupied Kuwait two months ago, according to a report issued today by Amnesty International.

Among those executed were five members of a Kuwaiti medical team shot after they failed to save the lives of several critically wounded Iraqi soldiers, and a Kuwaiti hanged for allegedly harboring a U.S. citizen from the authorities, Amnesty officials said.

The London-based human rights organization summarized accounts obtained from about 50 people who have fled Kuwait in the past few weeks. "Their testimony builds up a horrifying picture of widespread arrests, torture under interrogation, summary executions and mass extrajudicial killings," Amnesty said.

President Bush has acknowledged his concern about alleged Iraqi atrocities inside Kuwait and has indicated that they are one factor that could lead him to abandon the go-slow approach of tough diplomacy and economic sanctions.

Iraq has denied reports of atrocities in Kuwait, which it insists is no longer a sovereign nation, and the Iraqi Embassy here refused comment on the Amnesty report. Analysts have said Iraq's crackdown in Kuwait is part of an attempt to destroy any lingering opposition.

Thousands of civilians have poured out of Kuwait in recent weeks, many of whom have told chilling stories of Iraqi terror and retribution for acts of resistance. Many of the stories have been impossible to verify because Kuwait has been cut off from contact with the outside world.

Amnesty spokesman Richard Reoch said the organization had interviewed dozens of people who fled the country and last month sent a team of two Arabic-speaking researchers to Bahrain to collect information. He said they returned with consistent accounts that matched other information Amnesty had compiled from London.

"Anyone fleeing Kuwait will tell you horror stories," said Reoch. "But our team interviewed a wide range of people, from doctors and lawyers to office workers, even a firefighter. They threw the net as wide as they reasonably could, and they tried to sift out information they could not confirm."

The Amnesty report said hundreds of people are being held at police stations, schools or other public buildings in Kuwait, and some have been shipped to Iraq. Those arrested include not only activists accused of involvement in armed attacks against against soldiers, according to Amnesty, but also people found in possession of opposition literature, the banned Kuwaiti flag or photographs of the deposed emir.

Some have also been arrested or executed for failing to replace photos of the emir with those of Saddam, according to Amnesty.

Those who have been released reported that torture is widespread and routine. Some said they were given electric shocks or beaten for prolonged periods. Others have suffered broken limbs, the tearing out of fingernails, toenails and hair with pincers or have been threatened with rape or execution, according to the report.

Dozens of unarmed civilians have been killed, according to Amnesty, including teen-age boys, who were shot in the head. It said the bodies of some young victims were dumped outside their homes. Doctors who worked at Kuwaiti hospitals told the researchers that Iraqi soldiers brought in dozens of corpses of young men, many of them shot at close range in the heart or head.

Reoch said several people gave accounts of the killing of the five medical staff members at one Kuwait City hospital. He said it happened after a surgical team failed to save the lives of several soldiers brought to the hospital with critical injuries after a shoot-out with resistance forces.