CHICAGO - Forces loyal to fallen Libyan leader Muammar Gadhafi committed a vast array of possible war crimes while battling rebels in Misrata, the country's third largest city, according to a report issued on Tuesday by a US-based human rights group.

The report by Physicians for Human Rights, titled "Witness to War Crimes: Evidence from Misrata, Libya," is based on interviews of residents in the Misrata area conducted in June. The authors say they provide evidence of "murder, torture, rape, forced internment, and disappearance."

The group says Libya's National Transitional Council must now move to prosecute people suspected of committing those crimes.

A popular uprising in Libya in February against Gadhafi's 42-year-old rule resulted in a civil war with rebels backed by a NATO bombing campaign from the air starting in March.

Misrata was liberated by rebels in May after a fierce three-month battle, and they now control most of the country.

"The abuses that we gathered evidence of in Misrata are some of the most egregious war crimes and crimes against humanity I've heard of in Libya," said Richard Sollom, deputy director of Physicians for Human Rights and author of the report.

"There has been some evidence of crimes committed by rebel forces, but certainly nothing anywhere near as widespread and systematic as those committed by Gadhafi's forces."

A single act can be deemed a war crime, but when troops commit "systematic and widespread" crimes against civilians, that is a crime against humanity, Sollom said.

As evidence of one such crime, the report includes a copy of a government order for troops to prevent fuel and supplies reaching the city of some 400,000 to 500,000 people.

Hospital, mosque targeted

The crimes detailed in the report are also consistent with what residents told Reuters reporters in Misrata during the summer and with video evidence provide by a member of the new city council's media committee.

For the report, the group focused on Misrata plus two towns immediately to the south of the city - Kerzaz and Tomina - which Sollom said were used as bases for Gadhafi loyalists during the government's bombardment of the city.

People interviewed for the report cited cases of torture, summary executions and allegations that Gadhafi loyalists targeted civilians, hospitals and mosques.

The report mentions the case of Mohammed, a civilian resident of the town of Kerzaz, who was left blind in one eye and suffered a broken jaw that he said he sustained while being tortured by government soldiers.

Video footage provided to Reuters shows at least one apparent rocket attack on a hospital, in which a room full of incubators for premature infants was hit.

Rebel fighters also showed a team of Reuters reporters in late July a mosque on Misrata's western front in the town of Dafniya, which they said had been targeted by Gadhafi loyalists. There were holes caused by tank and rocket fire on the west side of the mosque's minaret - indicating that government troops had inflicted the damage.

And in interviews residents of Misrata told Reuters in July that Gadhafi loyalists targeted civilians.

"Gadhafi's aim here was to kill as many people as he had to in Misrata in order to stay in power," said Fauzi al-Karshaine, a local businessman who was shot five time by Gadhafi troops on February 19 during a protest for greater freedoms by unarmed people in Misrata. "He does not care how many innocent women and children he has to kill to do it."

In June the International Criminal Court issued indictments against Gadhafi, his son and heir apparent Saif al-Islam and Libyan intelligence chief Abdullah al-Senussi.

Physicians for Human Rights recommends that to move forward, post-Gadhafi Libya must come to terms with its past and prosecute individuals suspected of having committed war crimes during the country's internecine conflict.

"The (ruling rebel) National Transitional Council has been saying the right things about moving forward and prosecuting war crimes," Sollom said. "But eventually Libya will have to deal with its past and hold individual perpetrators accountable."