GENOA, Italy (CNN) -- A demonstrator has been killed amid clashes in the Italian city of Genoa where the leaders of the world's major industrialised countries are meeting for an annual summit.
More than 100 people, including many from the security services, were wounded and more than 70 people detained. A police officer is critically injured although no details are yet known.
The clashes between police and protesters in the Mediterranean port town overshadowed news from the G8 summit itself, where leaders on Friday announced the creation of a $1 billion global AIDS fund and efforts to prevent a global recession.
The dead man was in his 20s but no more details had yet been released. His body is in the hands of a magistrate who will carry out an autopsy.
There are conflicting reports about the cause of the man's death. CNN's Alessio Vinci said some eyewitnesses had said the demonstrator was killed by a gunshot -- but he stressed these reports had not been confirmed.
According to other reports the protester may have been hit by a brick, or even a teargas cannister.
An Italian National Police spokesman said: "The demonstrator has an injury on his head. It is not clear if he was shot or was struck by a rock or brick."
A medic who had been following thousands of protesters rampaging through Genoa during the day described the incident in Piazza Alimonda, about two km (1.2 miles) from the Renaissance palace where Group of Eight leaders were meeting.
"He was hit twice, once in the forehead and once on the left cheek," Valeria Valerio, a medic with the anti-globalisation Genoa Social Forum, told Reuters.
"He had blood pouring from his mouth."
Reuters reported that after an ambulance took the body away, police withdrew, firing tear gas at a group of about 30 protesters who threw stones at them and shouted, "Assassins!"
Vinci said the "extremely violent and intense" clashes were continuing in a stadium nearby, with helicopters flying overhead and reinforcements being sent.
He added that the violence was caused by a limited faction of anarchists, who came to the Meditteranean city not to protest over the G8 summit, but solely to fight the police.
Brief outline of Genoa G8 security: - About $110 million has been spent on hosting summit. - At least 15,000 police and military troops deployed. - Police will wear anti-riot gear and be equipped with live ammunition, rubber bullets, tear gas, armoured personnel carriers and water cannons. - Surface-to-air missiles will be in place, while fighter jets, naval ships and minesweepers will be used. - A Red Zone which will ostensibly be closed to everyone apart from delegates and residents will be set up. Twelve foot barriers to be erected. - Rail, road and airport links will be shut, the port cleared and border controls patrolled. - Yellow Zone will act as buffer zone around the red zone. - U.S. President George W. Bush will not stay with other world leaders because of fear of terrorist attack. - Metal detectors, sniffer dogs and agents will stand guard at the luxury cruiser housing the leaders. A top U.S. aide said President George W. Bush regretted the "tragic" death.
"I understand that the president's been informed of the violence, of the injuries and the death," Gary Edson, deputy U.S. national security adviser, told reporters.
"The president regrets the violence, believes the violence is regrettable, the death is tragic, and the injuries to the protesters and the police officers are highly regrettable."
Italian police used tear gas and water cannons to try to stop the militants breaking through a ring of steel erected around the talks' central venue.
Earlier on Friday, police detained activists near the "red zone" as windows were smashed and black smoke rose from burning vehicles and rubbish bins.
About 200 protesters threw a petrol bomb into a local prison after breaking its windows before they were chased off by security guards.
An Italian paramilitary police van is attacked At one stage water cannons were used about 300 metres from the Renaissance palace where the leaders of the main industrialised nations, including Bush, were lunching.
A Reuters reporter said a policeman fired shots into the air from his pistol in an effort to force back the crowds in a separate incident in another part of the town.
Following the first day of top-level talks between the leaders of the U.S., UK, Japan, Germany, Italy, France, Canada and Russia, Italian Premier Silvio Berlusconi announced the creation of a $1 billion global health fund to battle AIDS and other infectious diseases in poor nations.
The world's economy, particularly how to prevent the U.S. slowdown from pushing the world into a global recession was another major issue discussed.
Up to 100,000 anti-globalisation and debt relief activists are expected to visit as the summit continues, with peaceful demonstrators waving placards saying "Zero Debt" and "People not Profits."
Former rock star and celebrity charity figure Bob Geldof, who is in Genoa to lobby leaders for debt relief for developing countries, condemned clashes, telling reporters: "I just don't think the violence will achieve anything. The debt campaigners have never been violent, and they have achieved a lot."
Italian Premier Silvio Berlusconi deployed about 20,000 police and soldiers to patrol the city and waters off the port in an attempt to stop the clashes that have accompanied all recent gatherings of world leaders.
Before arriving in Genoa, Bush criticised protesters: "For those who want to shut down trade I say this to them as clearly as I can -- You are hurting poor countries.
"For those who are going to use this opportunity to say the world should become isolationist, you are condemning those who are poor to poverty and we don't accept it.":
