KINSHASA/TOKYO - At least 30 people died when an overcrowded boat hit a rock and sank on the Congo river, sparking riots in which angry youths on the rampage set fire to public buildings, officials said Friday.

“There are 105 survivors and we have pulled up 30 bodies. The search is continuing,” provincial government spokesman Monulphe Bosso told AFP.

The accident occurred when an overcrowded boat hit a rock and sank Monday near the village of Yakusu II some 35 kilometres (20 miles) north of the eastern provincial capital of Kisangani.

“At its departure, in Kisangani, the boat embarked 39 people according to the register handed over to the authorities. Perhaps they were trying to cheat river surveillance services... as they took more passengers on board along the way,” Bosso said.

“They embarked many more people... the boat was carrying a lot of goods and was also crowded with people. They hit a rock” and it sank, he added.

A government delegation was heading Friday for the town of Isangi, the vessel’s scheduled destination, where rioting youngsters on Thursday went on the rampage. “They set fire to the offices of the river police and the naval force. They’re youngsters angered by the loss of their relatives, they say people (the authorities) are not rigorous enough” about making sure safety conditions are complied with, Bosso added.

Shipping disasters occur frequently, leaving many dead on the lakes and rivers of the Democratic Republic of Congo due to overcrowding on old and poorly maintained vessels, a lack of life-jackets and the fact that many people do not know how to swim.

At least 129 people died in December when an overcrowded boat went down on Lake Tanganyika, and in March a shipwreck on Lake Albert left 210 dead and missing.

Meanwhile, Japan’s coastguard said Friday that three foreign crew members had died among a group of 10 who were rescued after they abandoned a cargo ship that sank off the country’s northern coast.

The trio - two Chinese and one from Myanmar - were part of a group plucked from chilly waters in the strait separating Japan’s main Honshu and northernmost Hokkaido islands.

They were initially listed as “unconscious”. “They were sent to hospital where they were confirmed dead,” a local coastguard official said.

The 10 crewmen abandoned the ship just before it sank.  Among the seven other crew members are two Bangladeshis, including the captain, and five Chinese. They are in a stable condition.

The 1,915-ton Cambodia-registered Ming Guang was carrying scrap metal from the northern Japanese port of Hakodate to South Korea when it sprang a leak and began sinking late Thursday.