Israeli fire killed at least two Palestinian civilians in Gaza on Thursday, health officials said, in the latest violence rattling a fragile ceasefire as Hamas and Israel looked to implement the second phase of the US-brokered Gaza peace plan.

Medics said two men were killed by Israeli forces in eastern Khan Younis, in an area adjacent to where the army operates.

The Israeli military told Reuters it wasn’t aware of any casualties as a result of Israeli fire on Thursday.

The Gaza health ministry said Israeli airstrikes, tank shelling and gunfire have killed at least 490 Civilians since the truce took effect in October after two years of war that widely demolished the Palestinian enclave.

Israel said four soldiers have been killed by Palestinian militants in the small coastal territory over the same period.

By advancing to phase two, the US and mediator partners Egypt and Qatar must confront the more contentious issue of Hamas disarmament, which the group has long rejected. The plan also calls for deploying an international peacekeeping force.