Israeli forces in southern Lebanon opened fire on protesters demanding their withdrawal on Sunday, killing at least 22, Lebanese health officials said.
Under a deal reached between Israel and Hezbollah in November, Israeli forces were due to withdraw from southern Lebanon within 90 days.
But Israel said it cannot do so, because the Lebanese Army had not deployed forces to prevent Hezbollah from re-establishing its presence in the area.
Demonstrators, some of them carrying Hezbollah flags, attempted to enter several villages in the border area, with around 120 injured when Israeli forces opened fire, Lebanese health officials said.
The Israeli army blamed Hezbollah for stirring up Sunday's protests.
It said in a statement that its troops fired warning shots to "remove threats in a number of areas where suspects were identified approaching".
It added that a number of suspects in proximity to Israeli troops were apprehended and were being questioned.
Lebanese President Joseph Aoun said in a statement on Sunday that "Lebanon's sovereignty and territorial integrity are non-negotiable, and I am following up on this issue at the highest levels to ensure your rights and dignity".
He urged them to "exercise self-restraint and trust in the Lebanese Armed Forces".
Separately on Sunday, thousands of Palestinians were prevented from returning to their homes after Israel accused Hamas of violating a fragile ceasefire by changing the order of hostages it has released.
Under the Israel-Hamas ceasefire, Israel on Saturday was to begin allowing Palestinians to return to their homes in northern Gaza.
Israel put that on hold until Hamas frees a civilian hostage who Israel said should have been released Saturday. Hamas accused Israel of violating the agreement.
Israeli forces fired on the crowds on three occasions overnight and into Sunday, killing two people and wounding nine, including a child, according to Al-Awda Hospital, which received the casualties.
Israel's military in a statement said it fired warning shots at "several gatherings of dozens of suspects who were advancing toward the troops and posed a threat to them".
Hamas freed four female Israeli soldiers on Saturday, and Israel released some 200 Palestinian prisoners, most of whom were serving life sentences after being convicted of deadly attacks.
