The families of four South Korean sailors taken hostage by Somali pirates last year are pleading for help in securing their release.

The sailors were among the crew of the tanker MT Gemini who were captured on April 30, 2011, while traveling from Kenya to Malaysia. The pirates released most of the crew after the tanker's Singaporean owners paid a ransom reportedly totaling $6 million.

Family members spoke out for the first time at a news conference Monday, after keeping silent while the government and the ship's owner worked to free the hostages. South Korean media broke a blackout on the case last month, which the foreign ministry requested after a failed rescue attempt in November of last year.

The families said in a statement Monday that efforts to free the sailors have yielded no results, prompting them to make a “difficult” decision to plead for help from the government and the South Korean people.

Kim Jeong-sook, the wife of the tanker's chief mate, Lee Geon-il, told reporters about their frustration.

“We tried to hold this kind of news conference before, but the government and the company told us to stay quiet and just wait. So we trusted the company and the government and just waited.”

The families say they have received no word on the condition of the sailors. Lee Ji-sun, daughter of first engineer Lee Sang-hoon, emotionally expressed concerns about her father's health after nearly a year and a half in captivity.

“My father went to sailing to earn money for our family, just for lives of our family and kidnapped by the Somali pirates. My father has been detained in Somalia for more than 520 days where the condition of life is extremely severe. The condition of his body and mind must be exhausted. I wish my father comes back soon.”

The kidnappers released the vessel along with 13 Indonesians, five Chinese and three Burmese after the earlier ransom payment.

Maritime security industry analysts say the pirates continued to hold the South Koreans to express their anger with the South Korean navy's January 2011 assault on the hijacked MV Samho Jewelry in the Arabian Sea. Eight suspected pirates were captured or killed in that operation.

The families of the kidnapped sailors say the Somali pirates have demanded an “unreasonably large ransom,” and that the ship's owner is playing the leading role in negotiations.