The UN migration agency says the boat sank on Friday between a Comoros island and the French island of Mayotte.

At least 25 people, including women and children, have died after traffickers deliberately capsized their boat off the Indian Ocean nation of Comoros, according to the International Organization for Migration (IOM).

The boat sank late on Friday between the Comoros island of Anjouan, or Ndzuani, and the French island of Mayotte, on an often-used migration route on which thousands of people have lost their lives in recent decades, the IOM said in a statement on Monday.

Fishermen rescued five survivors on Saturday morning. The survivors said the boat had carried about 30 people of different nationalities, including seven women and at least six young children.

“IOM Comoros is saddened to hear about the deaths of at least 25 people after their boat was deliberately capsized by traffickers off Comoros Islands, between Anjouan and Mayotte on Friday night,” the statement said.

Anjouan, one of the three islands that make up the impoverished nation of Comoros, lies about 70km (44 miles) northwest of Mayotte, which became a department of France in 2011.

Despite being France’s poorest department, Mayotte has French infrastructure and welfare. Some refugees from Comoros pay smugglers to make the dangerous sea crossing in rickety fishing boats known as “kwassa-kwassa”.

Almost half of the Comoros’s 900,000 inhabitants live below the poverty line and many have no access to healthcare.

Comorans’ journey to Mayotte

The IOM statement cited a report from the French Senate that estimated that between 7,000 and 10,000 people had lost their lives trying to cross from Comoros to Mayotte between 1995 and 2012, but said this figure could be much higher.

Migrants are estimated to make up nearly half of Mayotte’s population of about 320,000, according to the latest French statistics from 2017. Of that group, 95 percent were Comoran, it said.

The Muslim-majority Comoros archipelago, situated between Mozambique and Madagascar, was a French colony. In 1974, Mayotte voted to remain part of France while the other islands sought independence and became the Comoros.

There had been two similar tragedies in the same area in the past three months, according to the IOM statement.

In September, a boat with 12 people on board including two children and an expectant mother left the coast of Anjouan and never reached Mayotte.

In August, eight people including a 12-year-old boy lost their lives in a similar incident, it said.