Photo taken on Nov. 26, 2018 shows three Ukrainian naval ships seized by Russia. (Xinhua/Sputnik)

MOSCOW, Dec. 8 (Xinhua) -- The Ukrainian sailors detained during the Kerch incident cannot be seen as prisoners of war as they were actually faced with criminal charges and the two countries are not in a state of war, the Russian Security Service (FSB) said Saturday.

"Ukraine has recently claimed that its servicemen were held as prisoners of war. However, the Ukrainian citizens are accused of a criminal offense," Mikhail Shishov, director of the FSB's investigative department, was quoted by Russian news agencies as saying at a briefing.

Under the Geneva Convention relative to the treatment of prisoners of war signed on Aug. 12, 1949, they cannot be considered as prisoners of war, as Russia and Ukraine are not "in a state of a military conflict or at war," he added.

On Nov. 25, Russian forces seized three Ukrainian naval ships as well as 24 sailors on board attempting to sail through the Kerch Strait from the Black Sea to the Sea of Azov, for they allegedly violated the Russian border. Kiev has since then constantly urged Moscow to release the captured sailors.

According to the FSB, the investigation of the criminal case against the Ukrainian sailors has been forwarded to its central office.

An inspection of the Ukrainian ships revealed that there were more weapons and ammunition than allowed, it added.

Consular access has been granted to all the Ukrainian sailors, who were also provided with lawyers, translators and the right to make phone calls, the FSB said.