Israel's military says a soldier has been killed in Gaza, the fifth to die since the beginning of a ground offensive in the territory.
The military statement today says prelimary reports show the paratroops officer was killed by Israeli fire late yesterday.
Three other soldiers were killed in a separate incident yesterday, apparently by an Israeli tank shell fired by mistake.
Gaza's crowded urban landscape increases the likelihood of so-called "friendly fire" incidents.
Another soldier was killed in a gunbattle Sunday.
The soldiers' deaths were the first significant losses suffered by Israel's military since it began an offensive against Hamas. Airstrikes began on 27 December, and a ground offensive began Saturday night.
The military says it has killed over 100 Palestinian fighters.