Pirates boarded a South Korean-flagged cargo ship near the Singapore Strait on Monday and robbed its crew of their money, clothes, and cellphones, South Korean officials say. Two of the ship's 22 crew members suffered minor bruises during the maritime robbery, South Korea's Ministry of Oceans said in a statement. Seven pirates used a speedboat to approach the 44,132-ton CK Bluebell before boarding it. One of the pirates was carrying a pistol while others were armed with knives, ministry officials said. The pirates took $13,000 in cash, clothes, shoes, and smartphones from the crew, according to the statement. The ship, carrying 68,000 tons of corn from Brazil, was to arrive at a South Korean port on July 30, the AP reports. Four of the cargo ship's crew members are South Koreans while the other 18 are Indonesians, according to the ministry. (More piracy stories.)