SEOUL , South Korea ( CNN ) -- Armed gunmen hijacked a Japanese freighter and its 23-member crew off the coast of Somalia , South Korean officials said Sunday . Somalia , which has had no functioning government since 1991 , is the world 's top piracy hotspot . Also a Russian patrol ship was able to thwart a hijack attempt on a Saudi Arabian vessel , a spokesman said Sunday . The 20,000-ton Japanese cargo ship was seized 96 miles ( 154 km ) east of the Gulf of Aden on Saturday , the South Korean news agency Yonhap said , quoting the country 's foreign ministry . Among the crew members , five are South Korean and 18 are from the Philippines , the ministry said . `` It was not yet learned who the hijackers are and whether the crewmen are safe , '' the ministry official told Yonhap . The Gulf of Aden , which connects the Red Sea and the Arabian Sea , has become a treacherous stretch for ships , particularly along Somalia 's coast . According to Noel Choong of the International Maritime Bureau , which tracks piracy attacks , there have been more than 84 attacks and 33 successful hijackings off Somalia 's coast this year . The hijacking came as the Korean government is considering sending a warship to join those from some other countries to combat piracy in the area . Meanwhile , a Russian naval spokesman confirmed reports that a Russian patrol ship thwarted the attempted seizure of a Saudi Arabian ship in the Gulf of Aden . The spokesman said the Russian ship was escorting a convoy when a Saudi ship in the convoy was attacked by gunmen on speed boats . An anti-terror team from the Russian ship prevented the seizure and the gunmen fled , the spokesman said .
Japanese ship carrying 23 crew , including five South Koreans and two Filipinos . Ship carrying chemicals sunk about 96 miles east of Somalia 's Aden port . Condition of crew not immediately known ; Somalia is the world 's top piracy hotspot . S. Korea is sending two ships to waters off Somalia to fight piracy .