Dakar: A fire ripped through makeshift shelters at a Muslim religious retreat in Senegal, killing at least 22 people and triggering a stampede, firefighters said Thursday.

The blaze broke out on Wednesday afternoon as worshippers gathered in the town of Medina Gounass in the southeastern region of Tambacounda, a senior official with the firefighting service told AFP.

The cause was as yet unknown, the official said.

Images of billowing clouds of smoke, the charred corpses of animals and devastation at the site circulated online, testifying to the fire’s impact.

While some victims were badly burnt, others were hurt in the panicked stampede triggered by the blaze, the firefighter added.

Around 20 of the injured are in a serious state and are being treated at the regional hospital in Tambacounda city, around 80 kilometres (50 miles) away.

The fire ripped through straw shelters constructed for the multi-day event, according to Senegal’s local press, allowing it spread rapidly through an open-air gathering packed with people.

Senegalese Muslims gather in their hundreds, even thousands, to worship at the site every year, and pilgrims were weighed down with food and luggage, the local press reported.

A similar incident at the same site in 2010 caused the deaths of six people and several injuries, Le Quotidien newspaper reported on Thursday.

Senegal’s poor record on fire safety was also thrown into the spotlight in 2013 when a fire in a Koranic school killed nine children, triggering an outcry and calls for tighter regulation.