JERUSALEM (AP) — The Israeli military ordered residents living in communities near the border with Lebanon to shelter in place and blocked roads early Wednesday following what it described as a “security incident” in the area.

The military declined to provide further details.

Israel has been bracing for a possible attack by the Lebanese militant group Hezbollah since an Israeli airstrike killed a Hezbollah fighter in neighboring Syria last month.

On July 27, the Israeli military said it had thwarted an infiltration attempt by Hezbollah militants in a battle that raged for more than an hour. Neither side reported any casualties and the Iran-backed Hezbollah denied involvement.

Israel considers Hezbollah to be its toughest and most immediate threat. After battling Israel to a stalemate during a monthlong war in 2006, Hezbollah is believed to be far stronger today.

Israeli officials estimate that Hezbollah possesses some 130,000 rockets and missiles capable of striking virtually anywhere in Israel. The group also has gained valuable battlefield experience by fighting alongside Iranian troops backing the forces of President Bashar Assad in the Syrian civil war.

Israel, which considers Iran to be its greatest enemy, has acknowledged carrying out scores of airstrikes in Syria it says were meant to stop Iran from transferring sophisticated weapons to Hezbollah.