At least four people are missing after an explosion on board a tugboat at Piram Bet island in Gujarat's Bhavnagar district in India on Friday.

According to initial reports, there were 14-15 people on board at the time of the incident.

The tugboat capsized and then sank following the blast in its diesel tank near Alang, according to the Gujarat Maritime Board (GMB).

Three crew members were rescued, said GMB vice chairman and CEO Mukesh Kumar.

The tugboat had been hired by customs officials to reach a ship anchored in the sea near the coast of Alang town in Bhavnagar district, around 220 km from Ahmedabad.

The blast occurred shortly after customs officials had boarded the larger vessel to carry out an inspection.

A video showed the tugboat sinking rapidly with fire and smoke billowing from the engine area.

One crew member can be seen grabbing a rope thrown from the ship.

At least four people are missing after an explosion on board a boat at Piram Bet island in Gujarat's Bhavnagar district on Friday. According to initial reports, there were 14-15 people on board at the time of the incident. Officials have rushed to the spot to rescue the people. The tugboat capsized following a blast in its diesel tank near Alang, the Gujarat Maritime Board (GMB) said.

No casualty or injury has been reported so far. Piram Bet is an island in Gulf of Cambay of the Arabian Sea. Three other crew members were rescued, said GMB vice chairman and CEO Mukesh Kumar. The tugboat had been hired by Customs officials to reach a ship anchored in the sea near the coast of Alang town in Bhavnagar district, around 220 km from Ahmedabad.

The area is known for its ship-breaking industry. "The tugboat had taken Customs officials for the inspection of a ship before it went for recycling at the ship-breaking yard. After the customs officials had boarded the ship, a blast occurred in the dietsel tank of the tugboat," said Kumar.

"The tugboat sank. While three crew members were rescued by those on the ship, four others are still missing. Our search operation is still on," the IAS officer added. Someone on board the ship captured the incident on a mobile phone and shared it on social media.

The video shows the tugboat sinking rapidly with fire and smoke billowing from the engine area. A crew member can be seen grabbing a rope thrown from the ship.