KINSHASA, Congo — Two boat capsizes in one weekend on Congo’s vast rivers have left 70 people dead and 200 others feared dead in unrelated incidents that were both characterized by heavily loaded boats operated with few safety measures, officials said today.

Early Saturday, a boat on a river in northwest Equateur Province hit a rock and capsized, provincial spokeswoman Ebale Engumba said today. She said more than 70 people are believed dead among 100 estimated passengers. She said officials are investigating why the boat was traveling through the darkness without a light.

Another boat tipping in Kasai Occidental Province left 200 people feared dead after the boat loaded with passengers and fuel drums caught fire and capsized in southern Congo, a survivor said today. Another survivor confirmed the account and said local fishermen refused to help drowning passengers who jumped off the crowded boat.

The incident in southern Congo would be the deadliest boat accident in the Central African nation this year, and among the worst in Africa this year.

The boats that traverse Congo’s rivers are often in poor repair and filled beyond capacity. The industry is not well-regulated and boat operators are known to fill boats to dangerous levels.

In the first incident in northwest Congo, Engumba said officials think the boat’s lack of lighting was responsible.

“We are going to arrest people involved who are in charge of regulating the boat’s movement who failed to stop that boat from traveling at night,” she said.

In the second incident, survivors said the boat was overloaded with people and goods. A local official said two of the boat’s crew were arrested but both refused to say how many people were aboard. The official said the passenger manifest apparently vanished in the fire.

Fabrice Muamba, who said he was on the boat when it caught fire Saturday night on the Kasai River, said he thought only 15 of the more than 200 people he thought were aboard were able to swim to safety. He said passengers began to jump overboard when the engine caught fire as it passed the remote village of Mbendayi, some 45 miles from the town of Tshikapa, which is north of Congo’s border with Angola.

Another survivor, a woman named Romaine Mishondo, said the boat was already packed with “hundreds” of passengers when it stopped some 10 minutes before the fire to pick up more people.

She said she did not know exactly how many people were aboard, but said the boat was so crowded it reminded her of “a whole market in the village full of people.”

But when the fire started and people began jumping overboard, she said nearby fishermen ignored drowning passengers’ pleas for help.

“Fishermen attacked the boat and started beating passengers with paddles as they were (trying) to loot goods,” she said. “The fishermen refused save passengers, instead taking goods into their pirogues. … I survived because I hung onto a jerrycan until another vessel passed by the scene and rescued us.”

Boat owner Mwamba Mwati Nguma Leonard said a survivor and an employee called to tell him the boat caught fire when workers spilled fuel and ignited the engine.

“At the moment I am crying after learning my boat caught fire,” Leonard said. “I was just told on phone that it was while seamen were putting fuel into the tank that an explosion occurred after the oil touched the vessel’s battery.”

He said he has asked police to arrest the boat’s managers as he believes they employed unskilled workers.

But he said he had no further details because he was in Congo’s capital, Kinshasa, some 500 miles from the scene, and because his employees on the scene did not answer his calls today.

“Since I am far away in Kinshasa, I cannot confirm at the moment the exactly what happened,” he said.

Leonard also confirmed Muamba’s account that the boat was carrying many drums full of fuel on its journey through Kasai Occidental Province. Leonard said the boat also was carrying sacks of maize. He said he did not know how many people were aboard.

Francois Madila, an official from the navigation department in the province, said police arrested two crew members and are investigating the incident. Madila said the sailors have not said how many people were aboard and that the passenger list appeared to have disappeared in the fire.

Other officials and witnesses in the remote area could not be reached for comment today.

The incident is the deadliest of several boating incidents reported this year in Congo.

In July, officials said at least 80 people died when a boat ferrying about 200 passengers to Congo’s capital capsized after hitting a rock.

In May, dozens of people died when an overloaded canoe capsized on a river in eastern Congo. And last November, at least 90 people were killed after a logging boat sank on a lake in Congo. The timber-carrying vessel was not supposed to be carrying passengers.

Congo is a vast country of jungles and huge rivers in Central Africa with little more than 300 miles of paved road. Many people prefer to take boats even if they do not know how to swim.