Dozens of bodies washed ashore Friday in Yemen after smugglers threw nearly 150 Somali migrants overboard in shark-infested waters, the latest such tragedy in one of the most lawless stretches of ocean in the world.

The Gulf of Aden between Yemen and the Horn of Africa already is notorious for Somali piracy. The hijacking of a freighter carrying a cargo of heavy weapons two weeks ago heightened concern over the chaos in a key shipping route — and prompted NATO on Thursday to send warships to help U.S. Navy vessels already patrolling the region.

The latest migrant deaths raised calls for those ships to also act against human trafficking in the same waters off Somalia, a country where there is no government control and armed groups are rampant.

"It's essentially the same problems that allow piracy and smuggling," said Roger Middleton, an expert on East Africa at the Chatham House think tank in London.

Dire economic conditions and violence in Somalia drive the waves of migrants, while the general lawlessness that gives pirates a free hand also opens the door for smugglers.

"People are very desperate," Middleton said. He welcomed the NATO deployment of ships against piracy, calling it "excellent news" that could also help in stopping human trafficking.

About 32,000 migrants have made the hazardous sea journey to Yemen this year — 22,000 of them Somalis, according to figures from the Yemeni government and the U.N. refugee agency.

Smugglers are known to cram dozens of men, women and children onto small boats and often beat and abuse the migrants during the journey, which can take up to three days. To avoid Yemeni patrols, the smugglers often dump their passengers far from shore and force them to swim the rest of the way.

In the latest instance, about 150 migrants departed Somalia on Monday, and when their vessel reached about three miles off Yemen's southern Shabwa coast, the smugglers ordered everyone off, said Ron Redmond, a spokesman for the U.N. High Commissioner for Refugees.

Twelve of the passengers were put on a smaller boat to take them ashore, while the rest were forced to swim. Redmond told reporters in Geneva that 47 people were believed to have survived, but about 100 were missing and feared drowned.

As of Friday, 30 bodies have been found washed up on shore and were buried immediately in keeping with Islamic customs of quick burial, a Yemeni security official said. He estimated that up to 118 may have drowned. He spoke on condition of anonymity because he was not authorized to talk to media.

In a sign of how frequent such drownings are, he cautioned that it was not certain whether all the 30 came from the boat, saying he could not rule out that other smuggling incidents occurred in the past week. During the first half of September, some 165 bodies were found on the shore, the Interior Ministry said.

The UNHCR estimates at least 230 migrants have died this year and 365 remain missing, including 100 from the latest incident. In 2007, more than 1,400 were reported dead and missing, according to the rights group Medecins Sans Frontiers.

The Gulf of Aden is not the only dangerous sea crossing for migrants. Hundreds of Africans die every year trying to make the journey across the Mediterranean to Spain, Italy and Greece.

There are many reports of boat people dying at sea off Spain, usually because overcrowded vessels capsize or break apart, and survivors often throw bodies of fellow travelers overboard when they die of exposure or starvation. But Red Cross officials in Spain said they have never heard of migrants in the area being tossed into the water alive.

The Aden traffic is particularly dense, with tens of thousands crossing a single concentrated geographical area — and, as MSF said in a June report, it is "largely ignored."

"This is one of the most dramatic situations in the world," the U.N. High Commissioner for Refugees, Antonio Guterres said in Geneva. "The way smugglers and traffickers treat people is absolutely outrageous and corresponds to one of the worst crimes that we can see in today's world."

He urged the international community to look "not only for pirates but also to look for these (human trafficking) situations in the Gulf of Aden."

NATO defense ministers agreed Thursday to send a seven-ship force to the region to deter piracy and escort U.N. food aid vessels into Somalia after the seizure two weeks ago of the Ukrainian freighter MV Faina and its cargo of 33 tanks and other heavy weapons. The NATO warships join vessels from the U.S. 5th Fleet, which already patrol the area.

Pirates have seized more than two dozen ships this year off the Horn of Africa, but the hijacking of the Faina has drawn the most concern because of its cargo.

Six U.S. warships are surrounding the Faina to prevent pirates from unloading the cargo, and a Russian warship is headed to the region. On Friday, a spokesman for the pirates threatened to blow up the Faina in three days if no ransom is paid.

A diplomat at the NATO meeting that decided on the deployment to the Gulf of Aden said deterring human trafficking was not discussed as part of its mission. The diplomat spoke on condition of anonymity to talk about the deliberations.

Lt. Nate Christensen, a spokesman for the 5th Fleet, said the U.S. Navy is focused on combating smuggling as well as piracy in the Gulf of Aden, and he expected the increase in the force will help.

"We look for weapons smuggling, drug smuggling, and human smuggling," he said. "That's part of the lawful maritime order that we try to create there." He would not provide details on how U.S. ships deal with migrant boats, citing operational secrecy.

"The more ships, the more coalition assets, the more people, the more navies we have involved in this problem, that's the way this is going to end," Christensen said. "It's not something the U.S. or six ships can solve on their own down there. It requires even regional governments to get involved."