At least two sailors died and 23 were missing Sunday when five ships sank in storms in the Black Sea and the Azov Sea, the official Russia Today Web site said.
The strong winds and high surf caused the Volgoneft-139 to split in two, spilling up 560,000 gallons of fuel oil, an official from Russia's Emergency Situations Ministry told CNN .
That is approximately 1,000 tons. In addition to the five ships that sank, many others were grounded, Russia Today reported.
The weather was hampering efforts to control the spill, which occurred in the Kerch Strait, the official said. The channel separates the Black Sea from the Sea of Azov.
The spill was moving toward the Ukrainian coast and Russia and Ukraine have set up a joint crisis center to deal with the disaster, the official said.
The Volnogorsk and the Nakhichevan -- each carrying about 2,000 tons of sulfur -- also broke apart as a result of the high waves and strong winds, a local transport official told RIA Novosti news agency. And a third sulfur-transporting vessel, the Kovel, went down later after striking the Volnogorsk, the agency reported.
A spokesman for the federal agency for sea and inland water transport, Aleksandr Davydenko, said conditions in the Kerch Strait were worsening. Twenty-foot waves and winds gusting to 78 mph were making the rescuers' task difficult, Davydenko said.
Emergencies Ministry spokesman Viktor Beltsov says the Volganeft-139 was anchored near the port of Kavkaz.
"At the moment specialists are trying to work out the size of the oil spill and the direction it's heading," he said. "We will alert the respective Ukrainian services if the spill moves in their direction."
Near the city of Sevastopol on the Black Sea, the storm wrecked a freighter carrying scrap metal. Two of its crew members were found alive, but 15 others were missing.
Another cargo ship was in distress.
Russia and Ukraine were working together to deal with the accidents, but according to news reports, strong winds had caused several more dry-cargo ships to run aground. Among them were Turkish vessels, a Georgian and a Greek ship.
Oleg Mitvol, deputy head of Russia's environmental watchdog and a member of the United Nations International Panel for Sustainable Resource Management, said the fuel oil spill could lead to long-term contamination.
"My forecast is that the coastline of the Kerch Strait and the strait itself will need deep re-cultivation" lasting 10 to 15 years, he said.
The storm's effects extended to Crimea, where power cuts led to suspension of heating and water supplies on parts of the peninsula.
"This is a major ecological catastrophe," said Vladimir Slivyak, head of Ekozashchita, or Ecodefense, a Russian environmental group, according to Interfax news agency.
The Kerch Strait is a key waterway for transporting fuel oil from the Caspian Sea onto tankers waiting in the Black Sea. The Volgoneft-139 was carrying fuel oil from the southern Russian city of Samara on the Volga River to an oil terminal in Ukraine, according to Interfax.
Previous fuel spills have been smaller than Sunday's disaster.
In November 2002, the Liberian oil tanker Prestige broke up and sank, spewing 64,000 tons of fuel oil into the waters and polluting thousands of miles along the Atlantic coast of France, Spain and Portugal.