Somali pirates have freed seven Indian sailors detained for close to four years in exchange for an undisclosed ransom, Somali officials and a maritime monitoring group said on Friday.
At one time the pirates made millions of dollars in ransoms from seizing ships sailing the Horn of Africa nation's waters, but increased patrols by international navies on the Indian Ocean have reduced incidences of piracy.
The sailors, held since the pirates hijacked the Panama-flagged ship MT Asphalt Venture in September 2010, were freed on Thursday. Eight of their colleagues were freed by the pirates along with the ship in April 2011 for a ransom.
Their captors said at the time that they would only release the seven sailors when their fellow Somali pirates held by Indian authorities were freed.
It was not clear if their demand had been met.
Kenyan-based Ecoterra International, which monitors maritime activity on the Indian Ocean, confirmed the sailors' release.
"The remaining seven hostages... were finally freed by their captors against a ransom and arrived in Mogadishu, the capital of Somalia, from where they will be flown directly to India," Ecoterra said in a statement.
Regional government officials were involved in the release of the sailors from their captivity in the town of Haradheere in central Somalia, officials said.
The last major hijacking incident off Somalia was early this year, when pirates seized a merchant ship in the Red Sea. This was the first successful hijacking in the region since 2012.
At the height of Somali pirate attacks in 2011, up to a dozen or more merchant ships were being held captive at any one time, often for multi million-dollar ransoms.
Reporting by Abdi Sheikh