Vietnam War by Associated Press photographers

Warning: Readers may find some of the images disturbing

Hovering US Army helicopters pour machine-gun fire into the tree line to cover the advance of South Vietnamese ground troops as they attack a Viet Cong north of Tay Ninh, near the Cambodian border, March 1965
To mark the 40th anniversary of the fall of Saigon and the end of the Vietnam War, an exhibition in London by the US news agency Associated Press showcases some of its most striking images taken by photographers embedded with US troops fighting the Communist Viet Cong.
A US paratrooper wounded in the battle for Hamburger Hill awaits medical evacuation at base camp near the Laotian border on 19 May 1969
During the conflict, AP's Saigon bureau won six Pulitzer Prizes for its war coverage, four of them for photography.
The body of an American paratrooper killed in action in the jungle near the Cambodian border is raised up to an evacuation helicopter in War Zone C, Vietnam, 14 May 1966
During the 1960s and 70s, the Saigon bureau gathered together a group of some of the most experienced photojournalists, including Malcolm Browne, Nick Ut, Eddie Adams, Hugh van Es, Dang van Phuoc and French-Vietnamese photographer Henri Huet who captured this shot in 1966 of the body of an American paratrooper killed in action in the jungle near the Cambodian border being raised up to an evacuation helicopter.
Horst Faas
The celebrated combat photographer Horst Faas served as AP's Saigon photo chief at the height of the war. Speaking to the BBC in 2007, Faas described his job in simple terms. "I tried to be in the newspapers every day, to beat the opposition with better photos. I didn't try to do anything grandiose. The photos were used and published and asked for, because Vietnam was on the front pages year after year."
Women and children take cover from heavy fire about near Saigon, Vietnam 1 January 1966
While in Saigon, Faas trained and mentored young Vietnamese photographers who made many of the war's defining images. Their daily photos from Vietnam helped inform the world of the traumas faced by people caught in the cross-fire of conflict.
First Cavalry Division medic Thomas Cole with one of his own eyes bandaged, continues to treat wounded Staff Sgt. Harrison Pell during a 30 January 1966 fire fight at An Thi in the Central Highlands between US troops and a combined North Vietnamese and Vietcong force
From a journalist's perspective the war in Vietnam was unique. It was the first war in modern times without censorship, where reporters and photographers were allowed virtually unrestricted access to the battlefields.
South Vietnamese General Nguyen Ngoc Loan executing a Viet Cong officer
AP photographers captured images that quickly became synonymous with the conflict: among the most notable was Eddie Adams's image of the South Vietnamese Gen Nguyen Ngoc Loan killing a Viet Cong officer with a single shot to the head. The image was to change the public perception of the war and haunted Gen Loan until his death.
Vietnamese children fleeing a napalm attack
Another was Nick Ut's picture of nine-year-old Phan Thi Kim Phuc - a young girl, running naked and terrified down the road after a napalm attack - which became one of the iconic images of the entire conflict.
An unidentified American soldier wears a hand written slogan on his helmet in June 1965
Nearly 60,000 US soldiers died in Vietnam, with more than 300,000 injured. For the Vietnamese, though, the figures were far higher, with estimates of more than half a million killed and many millions wounded.
Freshly landed US Marines make their way through the sands of Red Beach at Da Nang, 10 April 1965. They were on their way to reinforce the air base as South Vietnamese Rangers battled guerrillas about three miles south of the beach.
Vietnam: The Real War, A Photographic History by the Associated Press will run until the end of May 2015 at the Guardian News and Media's gallery, King's Cross, London.