Damaged buildings are seen after being hit by an Israeli airstrike on Tuesday in Beirut, Lebanon. AP

The United Nations has expressed its "grave concern" over the Israeli strikes on the densely populated southern suburbs of Beirut, Lebanon, on Tuesday, which resulted in scores of civilian casualties.

In a statement on Tuesday, Stéphane Dujarric, Spokesman for the UN Secretary-General, said, "As we await further clarity on the circumstances, we again urge the parties to exercise maximum restraint and call on all concerned to avoid any further escalation."

He added that the parties must urgently recommit to the full implementation of Security Council resolution 1701 (2006) and immediately return to a cessation of hostilities.

The UN Special Coordinator for Lebanon Jeanine Hennis-Plasschaert underscored that "there is no military solution and calls on Israel and Lebanon to use all diplomatic channels with a view to returning to a cessation of hostilities."

The Special Coordinator "is in close contact with key stakeholders and calls for calm."

WAM