The escalation comes as Lebanon and Israel prepare for talks between military delegations at the Pentagon on Friday, and for US-brokered talks early next week -- the fourth round since the latest Israel-Hezbollah war erupted on March 2.After heavy strikes that Lebanese authorities said killed at least 14 people including three children, Israel's military said it "precisely struck in Beirut", without identifying the target.A Lebanese military source, requesting anonymity, told AFP that "an Israeli strike targeted an apartment in the Choueifat area".AFPTV footage showed smoke rising from the area on the edge of Beirut's southern suburbs, a Hezbollah stronghold.An AFP correspondent said the first two floors of a residential building were damaged, and saw residents packing cars and leaving.It was the second Israeli strike on south Beirut since a ceasefire between Israel and the Iran-backed Hezbollah that was supposed to have taken effect on April 17 but has never been observed.

Aftermath of the Israeli airstrike in the Choueifat area south of Beirut © Ibrahim AMRO / AFP

Both sides accuse each other of violating it and justify their attacks by the other's alleged truce breaches.Hezbollah on Thursday claimed several attacks with rockets and drones on Israeli troops in south Lebanon.Spokesperson for the United Nations Interim Force in Lebanon (UNIFIL) peacekeepers Kandice Ardiel told AFP that last month's agreement "had a positive effect in lessening the violence, but (we) have seen an escalation in recent weeks, and an intense escalation in recent days".The force said in a statement that "Wednesday saw around 670 projectiles fired -- the highest level since 17 April".'Cultural landmarks'On Wednesday, Israel's military declared all areas south of Lebanon's Zahrani River -- around 40 kilometres (25 miles) from the border and including the cities of Tyre and Nabatieh -- to be "combat zones" and told residents to evacuate.This week, Israel vowed to ramp up operations in Lebanon and said it was expanding ground operations there.On Thursday afternoon Israel's military issued another evacuation warning for swathes of Tyre and surrounding areas.