Iran’s ambassador to the United Nations has formally alleged that four Iranian diplomats were killed in an Israeli strike on a hotel in Beirut on Sunday.

In a letter sent to UN Secretary-General António Guterres, Amir Saeid Iravani said the attack on the Ramada Hotel had been intentional and specifically targeted the diplomats after they had relocated there from their official residences.

He said the killing of four accredited Iranian officials, operating on behalf of a sovereign state while in another sovereign country, amounted to a serious violation of international law and what he described as an act of terrorism.

The strike hit the fourth floor of the hotel in central Beirut. Israel’s military said the building was hosting a covert meeting involving Iranian operatives at the time.

The Israel Defense Forces said the five people killed were members of the Quds Force, the foreign operations branch of Iran’s Revolutionary Guards.

Lebanon’s health ministry initially said four people had died and 10 others had been injured in the strike, though it did not identify those affected.