At least 30 migrants are feared to have drowned off Libya after their dinghy began to sink, the International Organisation for Migration (IOM) said Friday (local time).
Some 91 survivors rescued by the Italian coastguard on Thursday said the boat had been carrying between 120 and 140 people when it began to deflate, sparking panic and tipping some people overboard.
"As often happens, the dinghy, which had been inflated on the beach (of Misrata) just before departure, quickly began to deflate," IOM spokesman Flavio Di Giacomo told AFP.
"People panicked, they all rushed to one side of the dinghy. Many fell in the water, some drowned while others managed to pull themselves back on board," he said.
Rescuers said they recovered just one body.
The survivors, who hail largely from Somalia but also include Sudanese and Nigerian nationals, were taken to a reception centre on the Italian island of Lampedusa.
In a separate mission on Thursday, a heavily pregnant Nigerian woman pulled to safety from a dinghy along with 105 other migrants gave birth on board the coast guard ship that had rescued her.
IOM said to date some 118,500 people have arrived in Italy by sea from the start of the year.
Around 500 migrants from the Middle East hoping to reach Austria are still stranded at a train station near Budapest, nearly a full day since they faced off with Hungarian police and refused to be escorted to a collection centre.
The people also refused food and beverages offered to them, police said. They want to continue their trip to western Europe, with most eventually hoping to reach Germany and other, richer European nations and seek asylum there.
The migrants, mostly Syrians fleeing the war at home, boarded the train in Budapest at noon on Thursday local time after spending at least two days in Budapest, blocked by police from further travel.
But police stopped the train as it headed to Sopron, on Hungary's border with Austria, at Bicske, only 40 kilometres west, and ordered the migrants out, saying they must be registered at a collecting centre for migrants in the town.
Once registered in Hungary, that country is responsible under EU law for processing their asylum claim.
The situation was still unresolved nearly a full day later.
Hungary's conservative Prime Minister Viktor Orban meanwhile drew fire for the handling of the crisis.
His government has built a razor-wire fence along the border with Serbia to keep migrants out and plans to reinforce it with police and military patrols from mid-September.
Budapest is also set on Friday to pass a law against border trespassers, introducing a three-year sentence for those who illegally cross and five for those who damage the fence in the process. The measure would also pave the way for army patrols of Hungarian borders.
Orban on Thursday said the migrants are a German problem, since most want to reach that country. He added that Hungary does not want to shelter Muslims, citing the painful Ottoman occupation centuries ago.
"Sometimes one must feel shame because of Viktor Orban. He has spoiled much in Hungary, but also much when it comes to values in the European Union," Luxemburg Foreign Minister Jean Asselborn told the German television ZDF on Thursday night.
"It would be disastrous if we had to impose sanctions on countries to force them into showing humanity," he said when asked whether Hungary could be forced to treat migrants differently.
Police say the Roszke border crossing has been closed after 300 migrants escaped from a refugee border camp.