Israel carried out an airstrike on a Hamas militant in southern Gaza Wednesday in response to an earlier attack that wounded five Israeli soldiers, testing a fragile ceasefire in place since October.

The strike came as Israel received the remains of what may be one of the last hostages held in Gaza and prepared to allow Palestinians to exit the territory via the Rafah crossing with Egypt.

Under the ceasefire, Israel is exchanging Palestinian prisoners for hostages’ remains, with the next phases including a stabilization force, a technocratic Palestinian government, and Hamas disarmament.

The two remaining hostages are Israeli Ran Gvili and Thai national Sudthisak Rinthalak, whose bodies have yet to be fully confirmed, the AP has reported.

The Rafah crossing will only reopen for two-way movement once all hostages’ remains are returned, with Egypt supervising exits and expressing concern over a potential permanent Palestinian exodus.