Search and rescue teams using rubber boats have spread across Lake Toba in search of any survivors from a ferry accident in Indonesia

Rescue team member using rubber boat as relatives of missing passengers from a ferry accident at the Lake Toba wait on piers of Tigaras port in Simalungun, North Sumatra, Indonesia June 20, 2018.
Rescue team member using rubber boat as relatives of missing passengers from a ferry accident at the Lake Toba wait on piers of Tigaras port in Simalungun, North Sumatra, Indonesia June 20, 2018. (Reuters)

Family members waiting in desperation at a small port on Indonesia's Lake Toba for news of missing relatives performed mass prayers on Thursday as the search for more than 190 people unaccounted for after a ferry sinking continued for a fourth day.

Only 18 people have been rescued and four confirmed dead since the overcrowded ferry sank early on Monday evening in waters that officials say are up to 500 meters deep.

Budiawan, the head of the search and rescue agency in nearby Medan, told Indonesian TV that the captain was among those rescued. He gave no other details but local media reports said the captain was being questioned by police.

The disaster, likely Indonesia's worst sinking in more than a decade, has prompted President Joko "Jokowi" Widodo to call for an overhaul of safety standards for passenger boats. Ferries are an important means of transportation in the nation of more than 17,000 islands, which cover an area that would stretch from New York to London.

About a thousand people crowded Tigaras pier on Thursday, including several hundred relatives of victims, some weeping uncontrollably, others silent and pensive.

Each time a search and rescue vessel docked, relatives ran toward it, only to turn away with faces contorted in disappointment or crying out the names of loved ones when it became clear no family member had been found.

Members of a religious organisation tried to comfort people, organising mass prayers for Christians and Muslims that continued for an hour. Chanting of Quranic and Christian verses was interrupted by the sobs of relatives and onlookers also moved to tears.

Cellphone video taken from another ferry that attempted to rescue people after the sinking has spread widely online and on television. The video shows dozens of people struggling in rough waters and crying for help while several of them try to swim for an orange lifesaver apparently thrown from the ferry.

Maruddin Siagian, waiting with other family members for news of his younger brother, said they're haunted by those images.

"We hope the government will never stop the search, never stop, until all the victims are found," Siagian said.

"We're tormented waiting for news about him, without any certainty like this. Especially our mother," he said. "But we're determined to keep waiting until the body of our brother is found. For us, his body is precious, we want to bury him properly for his soul to be peaceful, and so we are too."

The 1,145-square kilometre (440-square mile) Lake Toba, formed from the caldera of an ancient super volcano, is a popular destination on the island of Sumatra and one of 10 stunning natural attractions in Indonesia that the government aims to develop as magnets for international and local tourists.

At a news conference on Wednesday evening, Jokowi said he'd instructed the search and rescue team involving divers and an underwater drone to find victims quickly and ordered the Ministry of Transport to review safety standards.

"This tragedy is a lesson for all of us to always be cautious and vigilant," Jokowi said. "The government will provide compensation to the families of the victims who died and guarantee the cost of care for those who need treatment."

The doomed ferry didn't have a passenger manifest, causing confusion about how many people were on board. On Wednesday, after the full scale of the tragedy emerged, Transport Minister Budi Karya Sumadi said the boat had a passenger capacity of 43 – making it five times over capacity – and equipped with only 45 life jackets.

Dudon Satiaputra, a former head of the national's police's forensic centre, said lake beds are typically covered with thick mud or sediment and this could hamper the search for bodies.

"What I know is there is lot of mud in lakes so drowned corpses usually sink into the mud, making them difficult to float," he said. "It is different with the sea, where the bloated body will float quickly to the surface."

Sarmini Nasution said she will not leave Tigaras until her 32-year-old son is found.

She said he drowned while trying to swim for a life jacket thrown from another ferry. The two friends he was travelling with reached it and survived.

"We've been waiting for three days without certainty," she said, weeping. "I'll wait until my son is found. I will not go home before carrying his body."

Source: AP