The Israeli air force says it struck Hezbollah targets in southern Lebanon in response to cross-border rocket fire in the most significant flare-up of tensions since a ceasefire brought uneasy calm to the region.

BEIRUT/JERUSALEM (Reuters) -Israeli artillery and airstrikes hit south Lebanon on Saturday after Israel said it had intercepted rockets fired from across the border, endangering a shaky truce that ended a year-long war between Israel and Lebanese armed group Hezbollah.

Hezbollah denied responsibility, saying it had 'no link' to the rocket launches and remained committed to the ceasefire. No group has claimed responsibility for the attack in Israel.