New Delhi, May 28 -- The Israeli military on Wednesday told residents across southern Lebanon to leave as it expands its operations there, saying in a statement that the military will "work with extreme force" against Lebanon's militant Hezbollah group.

The warning - which fell on the Islamic holiday of Eid al-Adha - came a day after Israeli troops clashed with the Iran-backed Hezbollah along a strategic river in southern Lebanon, with Israeli forces pushing farther north, days ahead of talks in Washington between Lebanese and Israeli delegations.

Wednesday's warning is the first that orders the Lebanese to relocate from the south since a ceasefire went into effect on April 17 and follows an escalation in the Israel-Hezbollah war.

Isra...