Qatar is a key US regional ally that is the location of a major American air base. It has hosted the Hamas political bureau since 2012, and has served along with the US and Egypt as a mediator in indirect negotiations between the group and Israel.

Tuesday afternoon’s air strike in northern Doha targeted residential premises housing several members of the political bureau of Hamas as they discussed the latest US proposal for a ceasefire and hostage release deal, according to Qatari officials.

Israeli officials initially told Israeli media that they were optimistic about the results of what they dubbed “Operation Summit of Fire”.

However, reports on Wednesday reflected their growing pessimism, with the suggestion that it might not have been as successful as they had thought. Some officials were quoted as saying the Hamas leaders may have been in a different part of the building.

Hamas said on Tuesday that the “heinous crime” had killed five of its members: Khalil al-Hayya’s son, Humam, the director of Hayya’s office, Jihad Labad, and bodyguards Moamen Hassouna, Abdullah Abdul Wahid and Ahmed al-Mamluk.

“We confirm the enemy’s failure to assassinate our brothers in the negotiating delegation,” it added, without providing any evidence.

By Wednesday evening, the Qatari interior ministry said authorities had identified the bodies of Humam al-Hayya, Labad, Hassouna, and Corporal Badr al-Humaidi, a member of Qatar’s Internal Security Force.

The ministry said efforts were under way by specialised teams to “identify two individuals reported missing”, adding that human remains had been discovered “in various locations”.

There was no mention of the whereabouts of Khalil al-Hayya, who has yet to appear in public