(CNN) -- Russian marines have stormed a tanker hijacked by pirates in the Gulf of Aden, freeing its 23 man crew and cargo of oil reported to be worth up to $50 million, naval officials said Thursday.
None of the crew was injured in the early morning rescue operation by marines from the Marshal Shaposhnikov. The Russian Prosecutor's Office said one pirate was killed and some were wounded. Ten pirates were taken into custody.
"The Marshal Shaposhnikov was ... fired upon by the pirates holding the ship. The Russian warship ... returned fire," the Eureopean Union's naval force reported.
"Eventually, the pirates surrendered and a boarding team from the Marshal Shaposhnikov arrived onboard the tanker, captured all the pirates and freed the crew."
The Russian-operated tanker Moscow University, which sails under the Liberian flag, has a crew of 23. It was on its way to China when pirates hijacked it Wednesday, the naval force said. The ship was carrying an estimated $50 million worth of oil at the time of the attack, according to Russian media.
The ship's owner credited quick action by the crew at the time of the hijacking for the success of the rescue operation.
"Due to wise steps taken by the vessel's captain Yuri Tulchinsky and his crew, all the 23 crew members hid in a special room inaccessible to pirates," said Serafima Shukshina, a spokeswoman for the Novorossiysk Shipping Line. "As a result, the pirates failed to take any crew members hostage, and couldn't take control of the ship despite their siege that lasted more than 20 hours."
Under the Russian law, the captured Somali pirates would face charges of group piracy with the use of violence and weapons, an offense carrying a maximum penalty of up to 15 years in prison, according to Vladimir Markin, a spokesman for the Investigation Committee of the Prosecutor General's Office.
Farther south off the coast of Tanzania, pirates failed in their attempt Wednesday to hijack a South Korean-flagged vessel, the naval force said. All those on board are reported to be well, it said.
EU NAVFOR escorts merchant vessels carrying humanitarian aid in the region and protects other vulnerable vessels in the Gulf of Aden and Indian Ocean.
Pirate attacks are frequent in the Gulf of Aden, which lies between Yemen and Somalia at the northwest corner of the Indian Ocean.