A surprise military exercise involving thousands of troops was launched Saturday night, simulating a sudden outbreak of fighting on the northern frontier, the Israel Defense Forces said.

The IDF said the three-day drill, dubbed “Hot Winter 2,” was aimed at “strengthening the readiness” of fighting units and the army’s logistics “for sudden events and various scenarios in the northern arena,” referring to the Iran-backed Hezbollah terror group in Lebanon and other Iranian proxies in the region.

Some 8,000 conscripts and 5,000 reservist troops are participating in the drill, the IDF said. The reservist troops were called up specifically for the drill, the IDF said.

“During the exercise, forces will practice dealing with being deployed in a sudden manner, in the face of operational scenarios in the northern arena, with an emphasis on the readiness of the logistics array, and cooperation between the ground forces units,” the IDF said in a statement.

While the drill was a surprise for the troops involved, the military said the drill was planned in advance, indicating that it did not stem from a new assessment.

The IDF has held several major drills focused on fighting in the north in recent months.

Earlier this month, the IDF’s 99th Division wrapped up a drill simulating sudden fighting on the northern frontier, and the Israeli Air Force conducted a series of joint aerial exercises with the US military simulating strikes against Iran and its regional terror proxies.

The 99th Division, established in 2020, includes several infantry, armored, artillery and special forces brigades.

The IDF said that drill placed an emphasis on defending against an attack on the border while moving logistical equipment to the frontier.

Earlier this year, the head of the IDF Technological and Logistics Directorate, Brig. Gen. Pini Ben Moyal said a series of drills the army had held raised “quite a few” issues with the way the army handles logistics. He said the military would examine these issues and find ways to address them, without elaborating.

The Iran-backed Lebanese terror group Hezbollah has long represented the most significant military threat on Israel’s borders, with an estimated arsenal of nearly 150,000 rockets and missiles that can reach anywhere in the country.

According to recent military assessments, should war with Hezbollah break out, Israeli cities could be bombarded with between 1,500 and 3,000 rockets a day and the death toll could quickly reach into the hundreds.

Other Iranian militias based in Syria could join in a potential battle alongside Hezbollah with missiles and drone attacks, according to other assessments.