Israeli Prime Minister Benjamin Netanyahu’s office said the strike on Nasser Hospital was a “tragic mishap” and that the military was investigating.

At least 20 people, including five journalists working for the international media, are said to have been killed in Israeli military strikes on Nasser Hospital in southern Gaza. The Israeli military has confirmed it carried out an attack nearby, but not why the building was hit. It says it’s ordered an initial inquiry.

Israel is facing fierce condemnation after a pair of strikes on a Gaza hospital killed five journalists as well as medical workers and others on Monday. At least 20 people were killed in the attack,