Pirates have kidnapped six crew members of a Turkish-controlled tanker off Nigeria, including its master.

The 15,900-dwt products tanker Puli (built 2007) was boarded by attackers early on Monday, Istanbul law firm Ulgener said in a statement issued on behalf the ship’s managers, K Tankercilik.

Reference sources are listing the Puli in the fleet of the Kaptanoglu Group.

The ship’s owners have started “working on every possible aspect to rescue the kidnapped crew members as soon as possible,” lawyer Fehmi Ulgener said in the statement.

Other crew members left onboard were not harmed and the ship was sailing to safety, he added.

A string of vessels have been attacked recently off Nigeria. Two unsuccessful attacks have been reported in recent days.

Last week, three kidnapped Greeks and one Philippino seafarer from the 16,500-dwt chemical tanker Madonna 1 (built 2008) were released from captivity.