Fifteen people were killed and more than 150 were missing after a boat carrying 300 passengers capsized near Mauritania's capital Nouakchott on Monday, the International Organization for Migration (IOM) said on Wednesday.

The Atlantic migration route from the coast of West Africa to the Canary Islands, typically used by African migrants trying to reach Spain, is one of the world's deadliest. Summer is its busiest period.

The IOM said the Mauritanian coastguard rescued 120 people and that 10 of them were taken to hospitals while efforts to locate the missing continued.

It said the passengers were travelling from Gambia and that they had spent seven days at sea before the shipwreck.

Ibba Sarr, a fishmonger at a waterside fishmarket in Nouakchott, said that strong winds in the past had two days moved the bodies closer to the shore and he saw around 30 bodies being collected from the beach.

"Surely other lifeless bodies will be discovered in the next two days," Sarr told Reuters by phone.

The stricken pirogue was located 400 metres north of the market, he said.

Mauritanian authorities did not respond to a Reuters request for comment.

More than 19,700 migrants reached the Canary Islands using the Atlantic route between Jan. 1 and July 15, 2024 representing a 160% increase compared to the same period last year, the IOM said.

An unprecedented nearly 5,000 migrants died at sea in the first five months of 2024 trying to reach the Spanish archipelago, migration rights group Walking Borders said in June.