Lebanon filed a complaint with the United Nations Security Council on Israel’s targeted assassination of Hamas deputy leader Saleh al-Aruri in the capital Beirut, which he described as “the most dangerous phase” of Israeli attacks on the country.

The complaint, dated January 4 but seen by Reuters today, states that Israel used six missiles in the attack that killed Arouri and adds that Israel is using Lebanese airspace to bomb Syria.

Saleh al-Aruri, second in command of the Palestinian Islamist movement Hamas, was killed by an Israeli drone strike in Beirut.

Israel has for years accused him of deadly attacks against its own citizens. However, a Hamas official said Saleh al-Aruri was “at the heart of negotiations” to end the war in the Gaza Strip and release hostages, citing diplomatic initiatives by Qatar and Egypt.