Gunmen hijacked a freighter with 23 crew off the coast of Somalia, South Korea said Sunday, as Somali pirates freed another vessel after securing a ransom and a Russian frigate repelled an attack on a Saudi ship, AP reported. In the latest hijacking, a 20,000-ton ship carrying unidentified chemicals was seized Saturday night, South Korea's Foreign Ministry said in a statement. The crew of the Japanese-owned Chemstar Venus consisted of five South Koreans and 18 Filipinos, the statement said. South Korean officials said they had no information on the condition of the crew or whether the gunmen were seeking a ransom. The Foreign Ministry said it will cooperate with Japan's government and the shipping company to win the early release of the sailors. The name of the Japanese company was not immediately available.