The Estonian cargo vessel Helt sunk off the Ukrainian port of Odessa after an explosion, reports Reuters. According to the shipowner, Vista Shipping Agency, the vessel might have collided with a mine. All six crew members have been rescued.

Two crew members left the vessel in a liferaft, the other four were initially reported as missing. Later, Ukrainian authorities said the other four had been rescued as well.

Earlier today, NATO issued a warning for ships sailing in the Black Sea. In addition to warning for mines, the organisation cautioned against electronic interferences and cyber attacks.

Also read: NATO warns shipping for mines and cyber attacks in Black Sea