U.S. Activist's Parents Demand Answers From Israel U.S. activist remains in critical condition after being hit by Israeli forces.

JERUSALEM, March 24, 2009  -- It happens every Friday. Palestinians, left-wing Israelis and international protestors gather in the Palestinian West Bank village of Ni'ilin to demonstrate against the construction of Israel's security barrier. It has been the scene of regular clashes with Israeli security forces.

But Friday, March 13, the usual stone-throwing clashes took a more serious turn when 38-year-old American peace activist Tristan Anderson of Oakland, Calif., was hit in the head by an Israeli tear gas canister.

Activists present said the canister was fired directly at Anderson from close range by Israel's security forces. He received treatment from Palestinian medics at the scene, and was then transferred to Tel Hashomer hospital near Tel Aviv.

He has had three brain surgeries since and has suffered serious damage to his frontal lobe. He remains in critical condition, according to his doctors.

Parents: Israel Must Take 'Full Responsibility for the Shooting'

On Monday his parents, Nancy and Michael Anderson, gave a press conference in Jerusalem.

"We want the Israeli government to take full responsibility for the shooting of our son," said an emotional Nancy Anderson. "I don't carry any negative feelings toward the soldier who shot our son. All I feel is love for Tristan and fear for his recovery."

The Israeli army said there was heavy stone throwing in the area at the time with many masked demonstrators involved. The Israeli foreign ministry said Anderson's injury was the regrettable result of rioting.

"Anyone taking part in a riot notorious for its violent and aggressive agitators armed with rocks and fire bombs has actively chosen to do so," read a statement released by the army's press office. "Such a person is no doubt aware of the inherent risks and has elected to participate regardless."

Anderson is a veteran of peace activism, but this was his first trip to Israel. He was here with his Jewish girlfriend on a three-month trip after which he was due to join his parents for a family vacation in Europe.

"He came to understand for himself what the Israeli-Palestinian conflict was all about," said Michael Anderson, his father. "It is ironic that the country in which he was shot is a democracy where it is supposed to be a duty for everyone to follow their conscience. We want to know what happened to our son."

Four Palestinians have been killed in the clashes in and around Ni'ilin during the past year. Israel's security barrier, which Israel claims is designed to prevent attacks by Palestinian suicide bombers, will separate villagers from 400 acres of their farm land.