By Stephanie Nebehay and Charlotte Steenackers
GENEVA/BRUSSELS (Reuters) - About 180 Ethiopian and Somali migrants, many weakened by hunger and drought in their home countries, were forced from a boat into rough seas off Yemen by smugglers on Thursday and 19 were presumed drowned, the U.N. migration agency said.
The International Organization for Migration (IOM) had earlier estimated the death toll higher, at 55.
It was the second such deadly incident in as many days off Shabwa province in southern Yemen, where 50 teenage African migrants were "deliberately drowned" on Wednesday by a smuggler who forced 120 passengers off his boat, the IOM said.
"Throughout the journey, migrants had been brutally treated by the smugglers," it said in a statement that described migrants being forced to squat during the 24-36 hour journey to save space, with no access to a bathroom.
"If one of the migrants accidentally moved, he would be beaten or even killed," the IOM said.
Twenty nine dead bodies washed up on the shore after Wednesday's tragedy while 27 others made it alive to the shore, it said.
"They were shocked, exhausted and quite desperate," Laurent de Boeck, the IOM Yemen Chief of Mission, told Reuters in an interview in Brussels.
Smugglers were pushing migrants into the sea away from the mainland for fear of government boats, amid reinforced border controls, or to avoid encountering armed groups on shore in the war-torn country. They were then going back to Africa to pick up more migrants.
"The smugglers are panicking," de Boeck said, adding that reinforced border controls along the coast could be having a counter-productive effect.
IOM spokeswoman Olivia Headon said dropping migrants off near the shore could mark the start of a new trend.
"These people are really thin. There is an ongoing drought situation in Somalia and Ethiopia. Some may not have had much strength to make it alive to the shore," she added.
Referring to the 19 people feared drowned in Thursday's incident, the IOM statement said: "Staff from IOM... found six bodies on the beach – two male and four female. An additional 13 Ethiopian migrants are still missing (unaccounted for)."
Already this year 55,000 migrants have taken the hazardous route from the Horn of Africa to Yemen to seek opportunity in the Gulf region, IOM said. The majority of migrants are young males between the ages of 12 to 25 from Ethiopia, it says.
The route is popular because it is cheaper than others, but when they arrive migrants often fall victims to abuse.
Yemen itself is riven by a two-year civil war in which forces loyal to the Saudi-backed government are pitted against Iranian-backed Houthi rebels.
Rescue operations at sea and policing to clamp down on the situation are extremely limited in the region, de Boeck said.
"The difficulty is also that this is a criminal network which is organized not only in Yemen but also in Somalia, in Djibouti as well as Ethiopia," he added.
(Reporting by Stephanie Nebehay in Geneva and Charlotte Steenackers in Brussels; Writing by Stephanie Nebehay and Alissa de Carbonnel; Editing by Richard Balmforth and Gareth Jones)