At least 13 people died when a boat with more than 100 passengers capsized off the coast of India’s financial capital Mumbai after colliding with an Indian Navy boat on Wednesday, officials said.

The navy said 99 people were rescued with efforts ongoing for others.

“An Indian Navy craft lost control while undertaking engine trials in Mumbai Harbour due to engine malfunction. As a result, the boat collided with a passenger ferry which subsequently capsized,” the Navy said in a statement on X.

Local TV channels showed a boat carrying at least five people hitting the passenger vehicle, causing the accident.

“The speedboat crashed into our boat and water started entering our boat and it overturned. The driver asked us to wear lifejackets,” a passenger on board the vessel told the ABP Majha news channel. “I swam for fifteen minutes before I was rescued by another boat,” said the passenger, who did not identify himself.

The privately-owned passenger boat, called Neelkamal, was heading towards the Elephanta caves, a popular tourist destination off the coast of Mumbai, when it capsized, the Brihanmumbai Municipal Corporation said.

The caves, which see a steady stream of tourists throughout the year, are a Unesco heritage site and were constructed in the 5th-6th centuries AD. Boats from the Gateway of India, Mumbai’s southernmost point, make regular trips to ferry tourists to the site, an hour away.