Just a few days after Pakistan’s Gilgit-Baltistan territory formed a climbing police force in response to the 2013 murder of 11 foreign climbers, two militants on trial for the crime attempted a jailbreak. One of the men escaped, and prison guards killed the other, according to the AFP.

The Pakistan Tribune reports that four prisoners smashed the main gate of Gilgit’s District Jail at 3 a.m. on Friday. Habib-ur-Rehman, a key suspect in the Nanga Parbat case, escaped along with a man imprisoned for an unrelated crime. Police are searching for the pair.

The massacre on Pakistan’s 26,660-foot Nanga Parbat is unprecedented in mountaineering history. As many as 20 people disguised as paramilitary officers hiked to base camp on the mountain’s Diamir side and shot 11 climbers: two Chinese citizens, one American, three Ukrainians, two Slovaks, one Lithuanian, one Pakistani, and a Sherpa from Nepal. The Sunni Muslim branch Tehrik-i-Taliban Pakistan later claimed responsibility for the attack as revenge for an American drone strike.

Read mountaineer and author David Roberts’ investigation into the Nanga Parbat murders, which Outside published a month after the incident.