Hamas says a member of the militant group has been killed in an explosion along Gaza’s fence with Israel.

The Islamic group’s military wing says the member was killed and another injured during a “holy mission.” Such language is used when explosives meant for an attack on Israel explode prematurely.

Israel’s army said it was not operating in the area at the time of the explosion early Sunday.

Fighting has escalated since an Israeli man was killed in a mortar shell attack on southern Israel on Friday. In retaliation, Israeli forces fired missiles that killed five Hamas militants.

Gazan militants fire rockets and mortars daily. Israel frequently launches airstrikes and ground operations in Gaza against the rocket squads.