MOSCOW/KYIV – Four pyrotechnicians of Russia's Ministry of Emergency Situations and a security guard were killed on Thursday during the disposal of unexploded Ukrainian ordnance in Russian-controlled Sevastopol, authorities said.

Regional Governor Mikhail Razvozhayev said that the men were clearing the area of debris following a Ukrainian attack when the unexploded ordnance detonated, causing them fatal injuries.

Authorities in other Russian regions have also reported casualties during Ukrainian attacks on Thursday.

According to the regional operational headquarters of Belgorod, one person was killed in the village of Varvarovka, and five others were injured in the settlement of Krasnaya Yaruga as a result of Ukrainian drone attacks.

ALSO READ: Ukraine says it strikes major Russian petrochemical complex

In the Kursk region, a woman was injured due to falling drone debris, said regional governor Alexander Khinshtein. 

Russian strike on passenger train

Also on Thursday, two people were killed in a Russian drone strike on a passenger train in Ukraine, Ukrainian state railway company Ukrzaliznytsia reported.

The train, carrying 340 passengers, was hit by a jet-powered drone in the southern Odesa region, the company said.

A train driver and his assistant were killed in the attack, it said.

The passengers were unharmed and evacuated to the city of Odesa, according to the Odesa Regional Military Administration.

Exchange of fallen soldiers' bodies

Separately, Russia and Ukraine have conducted a fresh round of exchanges of the bodies of soldiers.

Ukraine said on Thursday that the bodies of 261 people were returned to the country.

The remains, according to the Russian side, were those of Ukrainian military personnel, Ukraine's Coordinating Headquarters for the Treatment of Prisoners of War said in a statement.

Law enforcement investigators, together with representatives of expert institutions, will work to identify the repatriated bodies, the agency said.

READ MORE: 1 killed, 12 injured in missile, drone attacks on Kyiv

Russia's RBC news outlet reported on Thursday that Moscow had received 24 bodies handed over by Kyiv, citing a Russian lawmaker.