DAKAR, Senegal - Scores of migrants who spent days at sea were missing and feared dead Sunday after their boat wrecked off Senegal's coast, the Red Cross said.

About 150 people were believed to have been on the small wooden boat, two dozen of whom were rescued by fishermen Saturday near the northern Senegalese city of St. Louis, said Red Cross spokesman Mama Niang. It was unclear exactly what happened to the boat.

Security authorities confirmed that 24 people were rescued, but they would not comment on any deaths because police had not finished interviewing the survivors.

"All of them were taken to the hospital and they aren't yet in a state to speak," said Lt. Mohamadou Moustapha Sylla, spokesman for a European-Senegalese task force working to stop the tide of illegal migrants heading to Spain's Canary Islands in an attempt to gain a toehold in Europe.

He said the survivors were gravely dehydrated and undernourished after days at sea.

The boat left Dec. 4 from around the southern Senegalese town of Djiffer, more than 180 miles from St. Louis, Sylla said.

More than 22,000 people have been caught trying to reach the Canary Islands from Africa this year, the highest total ever, and hundreds are believed to have died along the way. Many migrants leave from coastal northwest African countries such as Senegal and Mauritania.

Last week, a migrant boat wrecked in Senegal's capital, Dakar, and close to 30 people were rescued. One person died at sea and three people later died in the hospital, Sylla said.

Undocumented migrants from countries with which Spain has automatic repatriation agreements are generally sent back home. But Spain has such arrangements with just a few countries in Africa.

People who cannot be sent home usually end up on the streets, either in the Canary Islands or the Spanish mainland.