While two of them – Mohammed Yusuf Ali Hasan and Mohammed Somal Mohammed Rafiq – managed to swim to safety, the others were swept away. Bodies of the three girls were later recovered, police said.

The Raigad police, under whose jurisdiction the incident took place, have launched a search for the four missing students.

The survivors told the police they were students of the MHSS Collegeof Engineering located at Byculla.

There have been similar incidents in the past when visitors to the Alibaug fort have been swept away by strong currents, particularly during the monsoon.

Usually, picknickers venture into the sea and wade through the water during low tide but are often caught unawares by the high tide on their return from the fort. The narrow coastal stretch between the fort and the shore is also dotted with large boulders, which adds to the danger.

Incidentally, the fort is located bang opposite the Raigad collector's bungalow and those of other senior government officials.

The search and rescue operations were carried out by the Raigad police in association with the fishermen of the region. Investigations are underway.