Thiruvananthapuram | The Indian Navy on Sunday joined the search operations for three fishermen who went missing following separate boat mishaps in Kollam and Thiruvananthapuram districts, officials said.

INS Kalpeni sailed out from Kochi on Saturday night for the search operation, a defence spokesperson said in a statement.

The vessel was anchored one nautical mile off Neendakara on Sunday morning, the statement said.

"A specialised Indian Navy diving team is onboard the ship. Marine Enforcement Wing was contacted for localising the diving position further. A Marine Enforcement boat is maintaining its presence in the vicinity of the ship," the statement said.

The search involving Indian Navy divers commenced around 10 am off INS Kalpeni, officials said.

"The divers are also utilising portable SONAR. The SONAR increases the capability of the divers for underwater surveillance and diving operations," the Defence Spokesperson said.

Coastal Police officials said that the Navy will first focus on the search for Gautam Krishna, who went missing after a fishing boat capsized off the Neendakara coast.

Later, their service would be utilised for searching other missing fishermen in Muthalappozhi and Vizhinjam, officials said.

The search operation by the Coastal Police, Marine Enforcement Wing of the Fisheries Department, and Coast Guard entered its 10th day on Sunday for Gautam Krishna, John, and Shijin, who went missing in separate fishing boat mishaps at Neendakara, Vizhinjam, and Muthalappozhi on July 31.

Family members of the missing persons had earlier protested, alleging lapses in the search operation, prompting the state government to seek the assistance of the Indian Navy.

Opposition parties also attacked the state government, alleging a slow response from the authorities in tracing the missing persons.

Meanwhile, Union Minister Suresh Gopi on Sunday said he would continue efforts to trace Gautam Krishna, a fisherman who went missing after a fishing boat capsized off Neendakara.

In a Facebook post, Gopi said Krishna’s mother had appealed to him to consider her as his own sister and stand with her in the search for her son.

Recalling her emotional appeal, Gopi said, "A representative of the people, more than that as a brother, this is the promise I gave that mother. This brother considers you his own sister and will be with you. I will go to any extent to bring that son back.”

Gopi said the fishing boat capsized after being caught in strong waves and the family was yet to recover from the shock of the tragedy.

He said he had been in constant contact with senior officials concerned and would not allow the search operation to slow down for any reason.

"All resources have now been mobilised to intensify the search in the sea," he said.

Gopi said a vessel carrying Navy divers had resumed an emergency search operation at sea and Coast Guard helicopters had intensified aerial surveillance.

He also said Indian Oil is extending full support to the operation by ensuring uninterrupted availability of fuel and other facilities.

An emergency helipad was also being urgently prepared at Amritapuri with the cooperation of college authorities to speed up rescue operations, he said.

Gopi said he had complete faith that Gautam would return when the strength of the administration and collective prayers came together.

"I will stand by that mother until my last breath to wipe away her tears. I will not give up hope... We will fight," he said.