(CNN) -- Turkish officials are investigating reports of a hijacking following distress signals from a Turkish-owned freighter in the Gulf of Aden, a Turkish Foreign Ministry official said Thursday.
The ship, the Neslihan, first sent a call for help Wednesday from a location near Aden, Yemen, an official at the Turkish Maritime Agency said.
The region near Somalia is notorious for piracy; NATO earlier this month sent seven warships to try to boost maritime security there.
NATO is helping with the investigation into the possible hijacking, the Turkish Foreign Ministry said.
Both the Turkish Maritime Agency and the company that owns the vessel said there is at least one Turkish military ship in the area, but they could not say if it would be involved with any possible rescue negotiations or operations.
The ship's Istanbul-based owner, Ya-Sa Shipping Industry and Trading, has not been able to contact the freighter, company spokesman Fehmi Ulgener said.
He said Ya-Sa is waiting to hear the hijackers' demands. The company expressed concern for the safety of the 20 crew members, who are all Turkish, Ulgener said.
The vessel is carrying 77,000 tons of iron ore from Canada to China, he said. It carries a Marshall Islands flag.
More than 60 ships have been attacked by Somali pirates in the Gulf of Aden this year alone, compared with about half that number in 2007, according to a report released earlier this month by Chatham House, a London-based institute that analyzes international affairs.
The report found that ransoms already paid this year, totaling $18 million to $30 million, are helping to finance the war in Somalia.
Combined Maritime Forces, a U.S.-led naval coalition involving several nations, said there were five attempts to hijack ships off the coast of Somalia in just one day earlier this week.
Somali Prime Minister Nur Hassan Hussein said October 19 that NATO had a free hand to fight piracy as it saw fit.
"They have our full consent to fight against the pirates," he minister said at a news conference. "NATO can carry out any acts including military actions in our waters against the pirates," he added.