Two Indian vessels had approached the Iranian-flagged FV Al Kamar 786 around 165 kilometres (100 miles) southwest of the Yemeni island of Socotra, not far from the eastern tip of Somalia.

An operation was "currently underway by the Indian Navy towards rescue of hijacked FV & its crew," the navy said in a statement posted on X, formerly Twitter.

The statement added that nine armed pirates were believed to have taken over the vessel. It did not say how many crew members were aboard.

India's navy has been deployed continuously off Somalia since 2008.

It stepped up anti-piracy efforts last year following a surge in maritime assaults, including in the Arabian Sea and by Yemen's Iran-backed Huthi rebels in the Red Sea.

This month, the Indian navy rescued 19 crew members off the Maltese-flagged cargo ship MV Ruen, which had been hijacked by Somali pirates in December.

On Saturday, it brought 35 Somali nationals accused of the hijacking to Mumbai aboard the warship INS Kolkata, which had led the rescue operation, to face a piracy trial in an Indian court.