Russia’s Northern Fleet is scheduled to conduct extensive training exercises this week to test its ability to defend a submarine base from saboteurs, according to a report. The readiness drills will unfold weeks after Russian President Vladimir Putin ordered the Northern Fleet to full alert to test its readiness for combat.

The Northern Fleet will collaborate on the drills with Russia’s Federal Security Service, or FSB, as well as several other government agencies, according to Russian news outlet TASS. Naval units will employ unmanned diving vehicles, drones and live ammunition as part of a hypothetical battle against saboteurs mounting an amphibious attack.

“Taking part in the exercise are crews of a submarine division, anti-sabotage units, coastal units’ personnel and naval aviation. Tight interaction has been established between the authorities of the closed administrative entity with the regional offices of the federal security service FSB, Emergencies Ministry, Interior Ministry and anti-terrorist commission,” Northern Fleet spokesman Vadim Serga told TASS.

The Russian military’s extensive training exercises in recent months have drawn the ire of Western leaders and the NATO military alliance, who had already expressed concern about Russia’s annexation of Crimea last March and purported support of separatist rebels in Eastern Ukraine. Putin ordered the Northern Fleet in March “to full alert in a snap combat readiness drill” last month after the United States and NATO allies conducted drills near Russia’s territory in the Arctic, CNN reported. The Kremlin dismissed the readiness drill as routine.

Putin has vowed to spend billions to modernize Russia’s military by 2020, according to reports. Russia extended its long-range bomber patrols in November to reach as far as the Arctic Ocean and the Gulf of Mexico, and announced plans earlier this month to build a “self-sufficient” military unit in the Arctic by 2018. Thousands of Russian soldiers conducted five days of military drills in the Arctic in March.