Israel’s Defense Forces have launched Operation Northern Shield to expose and destroy tunnels, built by the Lebanese Shiite militant group Hezbollah, crossing into Israel, IDF Spokesman Jonathan Conricus said on Tuesday.

The army has not called up reserves, but reinforced its forces in the north. The northern command is on full combat alert and is ready for various unexpected circumstances and scenarios, the spokesman said.

Although the tunnels cross into Israel, they are not yet operational and do not pose an imminent threat to Israeli civilians, Conricus said. He did not elaborate on the number of tunnels.

"It will take time to neutralize and expose all the tunnels," the spokesman said.

The army declared an area around Metula, in northern Israel, a closed military zone.