MOSCOW, January 12. /TASS/. The preliminary investigation into the Ukrainian sailors detained in the Kerch Strait on charges of illegally crossing the Russian border has been extended until May 25, a source close to investigators told TASS on Saturday.

"The investigation of the criminal case has been extended until May 25," the source said, noting that the investigators also insisted that the arrest of the Ukrainian sailors should be extended until April 26, i.e. by three months.

Kerch Strait incident

On November 25, three Ukrainian navy ships illegally crossed Russia’s border and tried to carry out some illegal actions in Russian territorial waters later in the day. They ignored legitimate demands to stop issued by vessels belonging to the FSB Border Service and the Black Sea Fleet and continued maneuvering dangerously. In order to stop the Ukrainian ships, weapons had to be used. The three vessels were detained in Russian territorial waters.

A criminal investigation was opened into the border incident. The ships’ crew members - 24 Ukrainian nationals - have been arrested until January 25, 2019. They are charged with violating the Russian border under Article 322.3 of the Russian Criminal Code. If found guilty, they may face up to six years in prison.