"Six aged women died at Kachuberia temporary hospital due to heart attack. They had fallen senseless due to suffocation," state Sundarbans Development Minister Manturam Pakhira, told media.

"The mishap occurred as the pilgrims got imapatient due to the long queue at jetty number five in Kachuberi and tried to outdo others in boarding the vessel," he said.

Naval divers have been deployed to search for anyone who may have fallen into Muriganga river (distributor of the Hooghly river) during the mad rush, officials said.

State Panchayat and Public Health Engineering Minister Subrata Mukherjee said the pilgrims were involved in a mad rush to board the vessels in view of the approaching low tide which would have halted launch movement on the river for hours.

Around 1.6 million pilgrims from across India and abroad had gathered at Sagar island, around 150 km from Kolkata in South 24 Parganas district, this year for the annual Gangsagar Mela on Makar Sankranti. The bathing had started from Friday night.  

This island is considered auspicious by the Hindus, who converge here at this time of the year to take the holy dip and pray by offering a coconut at the Kapil Muni temple.

The Ganga Sagar Mela is rated as the second largest assembly of people after the quadrennial Kumbha Mela (fair).