Northern Fleet base in Murmansk region (Photo from Wikipedia)

An explosion occurred in the vicinity of the Russian Northern Fleet base in Murmansk, according to Andriy Kovalenko, head of the Center for Countering Disinformation at Ukraine's National Security and Defense Council.

"Murmansk hosts command centers, ammunition depots, repair docks, and fleet control points. It is also a testing site for weapons, including Zircon missiles," Kovalenko wrote.

He added that the base enables Russia to control Arctic sea routes and access the Arctic Ocean. It can host both surface ships and nuclear-powered submarines.

Ships of the Russian Northern Fleet are equipped with Kalibr missiles and conduct reconnaissance and counter-NATO operations in the Arctic region.

Pro-Kremlin Telegram channels reported two explosions in the Murmansk area. Local residents claimed shockwaves were felt several dozen kilometers away.

The explosions reportedly occurred on December 18 around 5:30 p.m. Kyiv time. The Russian authorities have not officially commented on the incident.

The straight-line distance from Murmansk to Ukraine is approximately 2,000 km.