Women mourn the victims of a ship accident in Budapest on Friday. Reuters

South Korean survivors of a tour boat which sank in Budapest say they barely managed to grab onto a drifting lifeboat while watching in horror as others around them struggled in the dark, rainy waters, shouting for help.

Only seven of the 35 people on the boat, including 33 South Koreans, were rescued. Seven others have been confirmed dead and 21 are still missing.

Meanwhile, Hungarian Prime Minister Viktor Orban said on Friday he had asked for a thorough investigation into a boat accident on the Danube River.

“One is shaken by this ... an accident happened where passengers had almost no chance for survival,” Orban told state radio. He also offered his condolences to the relatives of the victims. South Korean relatives of victims of the Budapest boat tragedy visited the scene of the accident.

“We have firmly decided that we won’t give up our hopes about the possibility of finding survivors,” South Korea’s Foreign Minister Kang Kyung-wha told a news conference in Budapest.

Kyung-wha arrived in the city with an emergency task force and on Friday visited the site of the crash along with her Hungarian counterpart Peter Szijjarto.

People light candles at a makeshift memorial on the banks of the river Danube in Budapest, Hungary, on Friday. AFP

Later in the day, officials escorted the relatives of victims, who had also arrived on Friday, to the riverbank.

Survivors said the small sightseeing boat had almost finished an hourlong night tour of the Hungarian capital on Wednesday and was nearly at its stop when a larger cruise ship hit it under a bridge near the parliament building, a city landmark. They said about 20 people were on the deck taking photographs or preparing to disembark. The others were in the cabin.

“I saw that big cruise ship coming closer to us but I never imagined it would ram our boat,” said a 31-year-old South Korean surnamed Jeong. She was quoted by South Korea’s Yonhap news agency.

Jeong said she and others on the deck were thrown into the cold Danube waters by the impact of the collision. Police said it took only seven seconds for the boat to overturn and sink.

She said she saw a lifeboat drifting near her and managed to get hold of it. She threw a rope to another South Korean tourist surnamed Yoon, who was near her.

“Our boat was turned over in an instant and began sinking,” Yoon, 32, told Yonhap. “All those on the deck fell into water and I think those staying in the cabin on the first floor probably couldn’t get out of the ship swiftly.”

While holding onto the lifeboat together, Jeong and Yoon said they shed tears when they saw the heads of other people coming up and down in the fast-moving river.

“The people had been plunged into the river in the darkness and shouted ‘Help me!’ while floundering in the waters. But I couldn’t do anything for them,” Jeong said, crying.

Another survivor surnamed Ahn, 60, said a crewmember of another sightseeing boat sailing nearby extended a hand to him after he was tossed into the river. But he lost his grip and was carried away by waters before he got hold of a drifting plastic object.

Yoon said rescuers were only able to pick up those who were in lifeboats or clinging to them, or who held the hands of people extended from other nearby boats. Yoon said she saw the cruise ship that rammed her boat keep sailing without stopping to help with the rescue after the collision.

Police launched a criminal investigation and detained and questioned the Ukrainian captain of the cruise ship late on Thursday. The 64-year-old man is suspected of endangering water transport leading to a deadly mass accident.

Hungary’s state TV reported that all of the seven rescued people have been released from the hospital except one who is being treated for broken ribs.

A diver speaks with rescuers under Margaret Bridge in Budapest, Hungary, on Friday. AFP

Thirty South Korean tourists were aboard the sightseeing boat along with two South Korean guides and a photographer. Two Hungarian crewmembers are among the 21 missing.

The South Koreans, mostly family groups, were on a package tour of Europe. Yoon was travelling with her mother, aunt and uncle. After she was rescued, she called her father in Seoul to tell him that she and her mother had survived. The fate of her two other relatives is unknown.

Yoon’s father, Yoon Seung-yong, told the Seoul-based Hankyoreh newspaper that his daughter felt guilty because she had organized the trip. “She cried and said, ‘Dad, what should I do? I think this happened because of me.’”

Associated Press / Reuters