Ahmed Jibril, leader of a Palestinian terror group responsible for multiple hijackings, bombings and kidnappings, died in Damascus on Wednesday at the age of 83.

The Popular Front for the Liberation of Palestine-General Command (PFLP-GC), which he led, said he died at a Damascus hospital after having been sick for months, according to the AP. He reportedly had a heart condition.

In 1985, the PFLP-GC negotiated a prisoner exchange with Israel in which it traded three Israeli soldiers captured in the First Lebanon War for 1,150 security prisoners, including Sheikh Amed Yassin, a founder of Hamas. The deal was called the Jibril Agreement.

“Known for cross-border terrorist attacks into Israel using unusual means, such as hot air balloons and motorized hang gliders. Primary focus now on guerrilla operations in southern Lebanon and small-scale attacks in Israel, West Bank, and Gaza Strip,” the report said.

Jibril was born in Jaffa in 1938, the son of a Palestinian father and a Syrian mother. His family later moved to Syria, where he joined the Syrian army and became an officer. His group supported Syrian President Bashar Assad during the country’s civil war, according to AP.