Two Britons have been injured in separate G8 protests in Switzerland.
Martin Shaw had been dangling from a rope which was cut by police
Martin Shaw, a veteran protester from Ealing, west London, suffered multiple fractures after falling from a bridge in Lausanne.
And news photographer Guy Smallman, 31, from Brixton, south London, suffered serious muscle damage to his leg after a stun grenade exploded at his feet in Geneva.
Both men are being treated in Swiss hospitals.
Mr Shaw, 39, fell 20 metres (65 feet) into a river after police cut a rope to which he was attached.
He was understood to have been trying to block the traffic with the rope when the incident happened.
A policeman that had not noticed the two people
suspended... cut the rope with a knife to clear the passage
A woman who was connected to the other end of the rope, was hauled to safety onto the bridge.
The G8 gathering of world leaders in Evian, just across the border in France, has sparked violence between tens of thousands of demonstrators and police on both sides of the
In the incident involving Mr Shaw, Swiss officials said about 15 activists had staged a sit-down protest on the A1 expressway bridge, over the Aubonne river.
Police tried to lift the rope, with Mr Shaw and his fellow activist attached, because it was blocking traffic.
A statement on the government's official summit website said: "Several
policemen raised [the rope] to allow the passage of the vehicles.
"At the same moment, a policeman that had not noticed the two people
suspended... cut the rope with a knife to clear the passage."
Mr Shaw was taken by helicopter to hospital after falling into shallow water.
He was described as seriously injured with multiple fractures, although his life was not said to be in danger.
The Swiss statement added that a district magistrate had opened an
investigation into the accident.
According to the Independent Media Center website, the activists had tried to block the bridge by putting a rope across it, with a person attached to either end.
"The police turned up pretty quickly, but didn't really know how to deal with the
situation," an unnamed witness said.
The police went mad with stun grenades and were firing them off in all
injured news photographer
"They started arresting the activists that were on the bridge, dragging them
away but did not know what to do about the rope.
"The drivers in the traffic were getting quite upset and eventually the
police just decided to cut the rope."
Mr Smallman, 31, a photographer for Images Sans Frontieres, has undergone two hours of surgery in Geneva to repair the damage to his left leg.
He blamed police for "going mad with stun grenades" against a "completely peaceful" crowd.
The summit itself is protected by a 10-mile security cordon, but the protesters have been demonstrating in towns and transport routes around the perimeter.
Swiss officials estimated the numbers of protesters at 50,000, while protest organisers said they numbered 120,000.
The main protest on Sunday saw tens of thousands join a
cross-border march that was largely peaceful.
But there was rioting and looting in Lausanne and Geneva, with police responding with tear gas and stun guns.
The G8 countries are: the United States, Japan, Germany, UK, France, Italy, Canada and Russia.