Turkish media said the 10,700-dwt Basat (built 2008) was en route from Cameroon to Ivory coast when it was boarded by gunmen on 5 November.
All but two of the 14 Turks on board made it to the citadel on the vessel.
The pirates opened fire at random and stole valuables, as well as abducting Murat Yilmaz and Emrah Samancioglu.
Contact has been made over a ransom.
The vessel reached Abidjan a day later.
It is operated by Tune Chemical Tankers of the Netherlands. The company said it had no updates on the situation.
