NAIROBI, Dec. 18 (Xinhua) -- Somali pirates have released a Greek cargo ship after holding it for about six weeks, a regional maritime official confirmed on Friday.

Andrew Mwangura, the East Africa Coordinator of Seafarers Assistance Program (SAP) said the MV Delvina, which was hijacked by pirates on Nov. 5, was freed by Somali pirates late Thursday.

"The MV Delvina was freed late Thursday and was to reach Mombasa in the next two days but is not moving. She is drifting in one position where she was being held captive," Mwangura told Xinhua by telephone from Mombasa.

All the crew in the Green cargo ship which was seized in the Indian Ocean are unharmed and are well despite their 43-day ordeal.

The cargo ship was hijacked northeast of the Comoros Islands in the Indian Ocean. It had been sailing from Ukraine to Mombassa in Kenya.

The company gave no details on the crew, but the European Union's naval mission to the region said it numbers 14 Filipinos and seven Ukrainians.

Piracy has become rampant off the coast of Africa, especially in the waters near Somalia, which has been without an effective government since 1991.

Ransoms started out in the tens of thousands of dollars and have since climbed into the millions. An estimated 25,000 ships annually cruise the Gulf of Aden, off Somalia's northern coast.