In a separate incident, a child drowned in Touba, some 200 kilometres (125 miles) east of the capital Dakar, Niang said
Millions of people were making their journey home from the town of Touba in central Senegal on Sunday, a day after the so-called Magal ceremony -- the high point of the annual pilgrimage -- was held.
Multiple road accidents this week left 16 dead and 572 wounded as people made their way to Touba, said Moussa Niang, spokesman for the fighters, according to local media.
In a separate incident, a child drowned in Touba, some 200 kilometres (125 miles) east of the capital Dakar, Niang said.
In 2015, 15 people were killed in road accidents as pilgrims gathered for the Mourides' annual gathering.
The Mourides are one of four important Sufi brotherhoods followed by Senegal's Muslims, who overwhelmingly practise a moderate version of Islam while following the teachings of local spiritual guides.
The Mourides' holy city of Touba, founded by Ahmadou Bamba Mbacke in 1888, has grown to be Senegal's second-largest after Dakar, with some 1.5 million inhabitants.