More than 100 people died as a passenger ferry capsized in Tanzania’s Lake Victoria on Thursday. Thirty-seven people have been rescued so far, Mwanza Regional Commissioner John Mongella told AP.

Tanzania’s police chief Simon Sirro confirmed that the toll climbed over 100, reported AFP, quoting state radio TBC Taifa.

Government officials fear that the toll may go over 200. “I cannot speculate how many people had been on board,” said Mongella. “Right now our focus is on rescue.” Such ferries often carry hundreds of people and are overcrowded.”

Earlier, Mongella said 40 people had survived the accident. However, it was unclear if any new survivors had been found since rescue operations resumed with police and army divers on Friday morning.

Initial estimates showed that the vessel was carrying more than 300 people, reported The Guardian. However, it is difficult to ascertain the exact number of passengers since the person dispensing tickets has drowned with the machine that recorded the data.

The ferry, MV Nyerere, was travelling between the islands of Ukara and Bugolora. It capsized a few metres from the dock near Ukara Island in Ukerewe district, according to national ferry services operator Temesa. The cause of the accident is not known yet.

In 1996, more than 800 people were killed when passenger and cargo ferry MV Bukoba sank on Lake Victoria. In 2011, close to 200 people died when MV Spice Islander I sank off Tanzania’s Indian Ocean coast near Zanzibar. The following year, at least 145 people died in a similar accident.