BERLIN (AP) — A former guard at the Nazis' Stutthof concentration camp has testified at his trial that he once saw people being led into the gas chamber when he served at the facility.

Bruno Dey, a 93-year-old former SS private, went on trial Oct. 17 at the Hamburg state court. He faces 5,230 counts of accessory to murder for killings while he was at Stutthof from 1944-45, based on the logic that as a guard he helped the camp function.

News agency dpa reported that, when asked Friday by the presiding judge what exactly he saw from the watchtower, Dey replied: "That people were led in, into the gas chamber, that the door was locked."

He said he heard screams shortly afterward, but added: "I didn't know that they were being gassed."