An American demonstrator shot in the head by the Israeli military Friday remains in life-threatening condition after undergoing surgery overnight.

“His skull is fractured. Fragments of bone went into his brain,” said Anderson’s partner, 25-year-old Gabrielle Silverman, originally from Brooklyn, New York, speaking on the phone from Tel Hashomer Hospital in Tel Aviv Saturday.

Silverman said doctors had removed part of the right frontal lobe of Anderson’s brain and were working to “put his face back together,” to address trauma to his eye and forehead. The hospital is refusing to release further details, she said.

“It’s unclear how well he’s going to recover. He could die. He could recover completely. He could be severely brain damaged,” said Silverman, adding that Anderson’s parents are on their way to Tel Aviv from San Francisco.

Israeli soldiers shot 37-year-old Tristan Anderson, of Oakland California, in the forehead with a high-velocity teargas canister at a demonstration against the Israeli West Bank separation wall in the village of Ni’lin on Friday.

Palestinians and their international supporters hold demonstrations at noon every Friday in Ni’lin and other villages against the Israeli wall, which, if completed, will snake 723 kilometers through the interior of the West Bank. Israel says the barrier is for its security, but Palestinians see it as one of many means to confiscate their land and further fragment their territory. The wall was ruled illegal by the International Court of Justice in 2004.