More than 30 migrants were feared dead after a small boat headed for Spain’s Canary Islands sank Wednesday, two migration-focused organizations said, as they criticized Spain and Morocco for not intervening earlier to rescue the vessel’s passengers.

The groups, Walking Borders and Alarm Phone, said the boat held around 60 people. Spain’s maritime rescue service confirmed the deaths of two of the dinghy’s occupants, a child and an adult man, and said a Moroccan patrol boat had rescued 24 people.

Neither Spanish nor Moroccan authorities would confirm how many people had been on board the vessel or how many might be missing.

Walking Borders spokesperson Helena Maleno said in a tweet that 39 people had drowned, without giving further details, while Alarm Phone, which operates a trans-European network supporting rescue operations, said 35 people were missing.

The tragedy sparked criticism from migrant rights activists who said the boat was in Spain’s search-and-rescue region under international law, meaning Madrid should have led the operation instead of Rabat.

At the time of its sinking, the dinghy was in waters off the coast of Western Sahara. Although Morocco administers a majority of the former Spanish colony, its sovereignty remains under dispute and the United Nations lists it as a non-self-governing territory.

Spain’s state news agency EFE reported that a Spanish rescue service ship, the Guardamar Caliope, was about 46 kilometers, about an hour’s sail, away from the dinghy Tuesday evening.

The Guardamar Caliope did not aid the dinghy because the operation had been taken over by the Moroccan Rescue Coordination Centre in Rabat, which dispatched a patrol boat that arrived on Wednesday morning, about 10 hours after it had been spotted by a Spanish rescue airplane, EFE added.

The EU has said it and member states have been intensifying efforts to establish an “effective, humanitarian and safe” European migration policy.

Morocco’s Interior ministry has not responded to a Reuters request for comment and Morocco has not made any official communication about what happened.

The Canary Islands off the coast of West Africa have become the main destination for migrants trying to reach Spain, with a much smaller share trying to cross the Mediterranean Sea to the Spanish mainland.

The Atlantic migration route is one of the deadliest in the world. Attempts to reach the Canary Islands’ shores saw at least 559 people, including 22 children, die in 2022, according to data from the U.N.’s International Organization for Migration.

The migrants using the route are typically from several countries in sub-Saharan Africa.