Five Israeli soldiers were killed in Gaza, the military said, in one of the deadliest incidents of its kind since the war began in October.
Israeli media said the soldiers were accidentally shot and killed by Israeli tanks on Wednesday.
The incident occurred in Jabaliya, northern Gaza, where Israeli troops are fighting Hamas militants.
Troops returned to the town this week after previously withdrawing, saying Hamas had regrouped there.
Tens of thousands of civilians have fled Jabaliya since the Israeli Defense Forces (IDF) launched airstrikes on Saturday. Troops re-entered Jabaliya on Monday.
Fighting has intensified in recent days there and in the southern town of Rafah, where about half of Gaza’s 2.3 million civilians have taken refuge.
The United Nations says that some 600,000 Palestinians have since fled Rafah, and another 100,000 Palestinians have been displaced by the resurgence of fighting in the north.
The five Israeli soldiers killed in Jabaliya on Wednesday were all serving in the 202nd Battalion of the Parachute Brigade.
Israeli media quoted the Israel Defense Forces as saying it was investigating why they were hit by tank fire.
However, a preliminary investigation found that the soldiers occupied a building in the Jabaliya refugee camp, dozens of meters away from Israeli tanks also stationed in the area.
The investigation found that the tanker recognized a weapon inside the building and fired two shells at it.
Seven other soldiers were injured by tank fire, three of them seriously.
