JERUSALEM, Israel — The Israeli military on Tuesday said it had begun a “limited, localized” operation against Hezbollah targets in southern Lebanon, opening a new front in its war against the Lebanese militant group.

In a brief announcement, it said it was striking Hezbollah targets in areas close to the Israeli border, and that air force and artillery units were carrying out attacks to support the ground forces. It gave no details on how long the operation would last, but said the army had been training and preparing for months.

“A few hours ago, the IDF began limited, localized and targeted ground raids,” it said. “These targets are located in villages close to the border and pose an immediate threat to Israeli communities in northern Israel.”

The incursion came shortly after it was approved by Israeli political leaders and marked a new stage in Israel’s war against Hezbollah, an Iranian-backed terrorist group.

Earlier, American officials said Israel had launched small ground raids against Hezbollah and sealed off communities along its northern border on Monday as Israeli artillery pounded southern Lebanon.

State Department spokesman Matthew Miller said Israel informed America about the raids, which he said were described as “limited operations focused on Hezbollah infrastructure near the border.”

The sounds of airstrikes were heard throughout Beirut and smoke rose from the capital’s southern suburbs, where Hezbollah has a strong presence, shortly after Israel ordered residents of three buildings to evacuate.

There were no reports of direct clashes between Israeli troops and Hezbollah militants, who last engaged in ground combat on Lebanese soil during a monthlong war in 2006.

Israel and Hezbollah have exchanged fire almost every day since the war in Gaza began, displacing tens of thousands of people in Israel and Lebanon.

Israel says it will continue to strike Hezbollah until it is safe for families to return to their homes near the Lebanon border. Hezbollah has promised to keep firing rockets into Israel until there is a cease-fire in Gaza.

Hezbollah vowed Monday to keep fighting even after its longtime leader Hassan Nasrallah and other top officials were recently wiped out by Israeli strikes.

The group’s acting leader, Naim Kassem, said in a televised statement that if Israel decides to launch a ground offensive, Hezbollah is ready. He said commanders killed in recent weeks have already been replaced.