Israel mistakenly killed three hostages in fighting in the Gaza Strip, the country’s defense forces said, prompting fresh questions about the conduct of its military campaign after U.S. President Joe Biden called Israeli bombing "indiscriminate.”

During fighting in the Shejaiya neighborhood, Israeli forces identified the three as a threat and fired at them, Israel Defense Forces spokesman Daniel Hagari said. Two of the hostages were identified as Yotam Haim and Samer Talalka, and the identity of the third wasn’t released. The Times of Israel reported that the three were trying to escape their captors when they were killed.

The IDF will investigate the incident, which occurred on the same day that Al Jazeera said one of its cameramen in Gaza, Samer Abudaqa, was killed in an airstrike that also wounded one of his colleagues. Al Jazeera said rescuers weren’t able to reach Abudaqa because of the Israeli bombardment.