* Up to 500 migrants packed onto small boat
* UNHCR says all passengers were Eritrean
* UN, pope concerned about perilous migrant traffic (Updates death toll, adds ministers, UNHCR quotes)
By Massimiliano Di Giorgio
ROME, Oct 3 (Reuters) - At least 92 people died and scores were missing after a boat packed with up to 500 African migrants sank off the southern Italian island of Lampedusa on Thursday, the coastguard said.
Bodies fished from the water were laid out along the quayside as the death toll rose in what looked like one of the worst disasters to hit the perilous route for migrants seeking to reach Europe from Africa.
"It's horrific, like a cemetery, they are still bringing them out," Lampedusa Mayor Giusi Nicolini told reporters.
The coastguard said 150 survivors had been rescued so far of the between 400 and 500 migrants thought to be on the 20-metre (66 ft) boat that caught fire and sank about 1 km (half a mile) off the island.
The U.N. refugee agency UNHCR said it believed there were around 500 passengers, all Eritreans who had boarded in Libya.
Almost 500 people were reported dead or missing making the crossing from Tunisia to Italy last year, the UNHCR says. Numbers have been boosted by thousands of refugees from the civil war in Syria.
"I commend the swift action taken by the Italian coastguard to save lives. At the same time, I am dismayed at the rising global phenomenon of migrants and people fleeing conflict or persecution and perishing at sea," U.N. High Commissioner for Refugees Antonio Guterres said.
Migrants frequently land on Lampedusa, just 113 km (70 miles) from the coast of Tunisia, often picked up at sea by the Italian coastguard in dangerously overcrowded boats.
Pope Francis visited the island in July, on his first trip outside Rome, to draw attention to the plight of refugees. He said the death of people trying to reach a better life was like "a thorn in the heart".
The stream of migrants is a humanitarian and political problem for the Italian government. Some 15,000 reached Italy and Malta - 13,200 and 1,800 respectively - by sea last year, the UNHCR says.
Calling the deaths of migrants "an endless tragedy," Foreign Minister Emma Bonino said: "The rescue operation began immediately but it is getting more difficult because now the weather is getting colder, they don't know how to swim, they don't know where to go."
Interior Minister Angelino Alfano cancelled a news conference in Rome to fly to Lampedusa.
A fishing boat raised the alarm at around 7:20 a.m. (0520 GMT) and began pulling people out of the water before coastguard vessels arrived on the scene.
Just four days ago, 13 migrants drowned when their boat foundered off eastern Sicily.
Transport Minister Maurizio Lupi said more needed to be done to combat people traffickers who coordinate the transport of migrants in crowded and unsafe vessels.
"It is a task which we have to take on and which the international community and the European community have to take on as well," he said.
(Writing by James Mackenzie and Robin Pomeroy,; Editing by Angus MacSwan)