The UN human rights chief on Monday said that he is "deeply worried" about the rising risk of wider conflict in the Middle East, and called for an urgent de-escalation.
"I am deeply worried about the rising risk of a wider conflict in the Middle East and plead with all parties, along with those States with influence, to act urgently to de-escalate what has become a very precarious situation," Volker Turk said in a statement.
Turk reminded parties that human rights and the protection of civilians must be the top priority.
Stressing that civilians-mostly women and children-have already endured "unbearable pain and suffering" as result of the bombs and guns over the past 10 months, he said: "Everything, and I mean everything, must be done to avoid this situation spiraling further into an abyss that will only have even more terrible consequences for civilians."
Tensions have escalated between Lebanon's Hezbollah and Israel since Tel Aviv assassinated the group's senior military commander Fuad Shukr in an airstrike on a suburb of Beirut on July 30.
Hamas political chief Ismail Haniyeh was assassinated in the Iranian capital Tehran the following day in an attack blamed on Israel, although Tel Aviv has not confirmed or denied its responsibility.
Hamas and Iran have vowed to retaliate for Haniyeh's assassination, while Hezbollah has pledged to respond to Shukr's killing.
Fears have grown of a full-blown war between Israel and Hezbollah amid a months-long exchange of cross-border fire.
The escalation comes against the backdrop of an Israeli onslaught on Gaza which has killed more than 39,600 people since last October following an attack by the Palestinian group Hamas.