"Aris 13, that his ship and crew are now being held captive by a number of suspected armed pirates in an anchorage off the north coast of Puntland, close to Alula", the force said in a statement late on Tuesday.
He said efforts were under way to free the ship and a regional governor, whose name was not given, had been appointed to lead negotiations with the pirates. The pirates drained the tanks of the tanker and stole all the fuel on board, but also demanded for ransom to release the vessel.
Naval forces from the semi-autonomous state of Puntland and the pirates had clashed earlier Thursday after the pirates opened fire.
Officials said local elders negotiated the release of the Aris 13 and that as part of the negotiations, the pirates were allowed to leave the vessel and return to shore.
The tanker was forced to change course and head toward Puntland.
A pirate confirmed the release was made without a ransom payment, according to Reuters.
Lim urged the Federal Government of Somalia, as well as its regional authorities in Puntland to take immediate action toward the safe release of the eight Sri Lankan seafarers.
Somali pirates usually hijack ships and crew for ransom - and do not normally kill hostages unless they come under attack.
"Pirates on the ship fired on us and so the pirate boat escaped", the director general told Reuters news agency.
The Aris 13 on Monday reported being approached by two skiffs, John Steed with the organization Oceans Beyond Piracy said.
"They desperately need to show their grievances by seizing the boat", said Abdiwahab Ahmed, an elder in the coastal town of Alula.
But frustrations have been rising among local fishermen, including former pirates, at what they say are foreign fishermen illegally fishing in local waters.
The gunmen have told a local official that they are fishermen whose equipment was destroyed by illegal fishing vessels.
The Sri Lanka-flagged ship is owned by Armi Shipping SA and is operated by Aurora Ship Management, both based in the United Arab Emirates.
Though anti-piracy measures ended attacks on commercial vessels, fishing boats have continued to face attacks.