Kochi:  At least five persons were killed and several others injured after a major fire broke out inside a ship at Cochin Shipyard Ltd at around 11 pm on Tuesday.

The blast took place inside ballast tank of Sagar Bhushan, a drill vessel owned by Oil and Natural Gas Corporation (ONGC), which was undergoing repair at the Cochin Shipyard. However, the cause of the explosion is yet to be ascertained.

According to the sources, five people succumbed to their injuries while rest are undergoing treatment at the Medical Trust Hospital in the city. However, the condition of one is critical with over 45 per cent burns, hospital officials said. 

The deceased were identified as Ramshad, Kannan, Jayan and Unnikrishnan, all natives of Kerala's Vypeen and Jivin.

Meanwhile, two persons who were trapped inside the ship have now been rescued. 

The CSL spokesperson earlier on Tuesday said 11 people trapped inside the ship were evacuated and rushed to city hospitals. City Police Commissioner M P Dinesh visited the accident site and said those trapped on the ship were evacuated and the situation was under control now.

The shipyard was shut on Tuesday for Maha Shivaratri but the maintenance section was reportedly open with a few workers. Reports suggest as many as 200 workers could have been victims of the mishap if it had not been a holiday. 

Union Minister for Road Transport and Highways, Shipping and Water Resources Nitin Gadkari expressed shock over the loss of lives in the blast. "Shocked by unfortunate blast at Cochin Shipyard... My heartfelt condolences to bereaved families. I have spoken to Cochin Shipyard n asked him to provide all necessary medical support to victims n to initiate immed inquiry with help of concerned agencies (sic)," he tweeted.

Kerala chief minister Pinarayi Vijayan condoled the death of the five persons in the blast. In a Facebook post, he said directions have been issued to conduct rescue operations and provide urgent medical care to those injured in the blast.