"Our vessel (oil tanker MT DUKE - IMO: 9262259) was involved in a security incident on Sunday at around 0700 UTC. DUKE was attacked and boarded whilst on voyage from Luanda, Angola to Lome, Togo, with a cargo of fuel oil", the company said in a statement.
According to Dryad Global maritime security risk management company, six pirates have boarded the oil tanker, kidnapping 20 Indian crew members.
"We are concerned by the kidnapping of 20 Indian crew members (as reported by the Shipping agency) from the vessel MT Duke in the high seas off the western coast of Africa on 15th December 2019", spokesman for the Indian Foreign Ministry Raveesh Kumar said in response to a query on the incident.
He added that the crew's safety was its top priority, and it would cooperate with all relevant authorities to resolve the incident as fast as possible.
The official also added that the country's mission in Nigeria was cooperating with the local and neighbouring countries' authorities on the matter.
"The safety of hostages is paramount and we continue to engage with Nigerian authorities and other stakeholders closely on the recent incidents", Kumar stated.
According to the ministry, this is the third incident of Indian nationals being kidnapped in the region this year. The most recent happened earlier in December, when media reported that 19 Indian nationals were taken from the Nave Constellation vessel off the Nigerian coast.
