At least 86 people have died in a riverboat accident in the Democratic Republic of Congo, the presidential office said on Wednesday. The boat sank in the province of Maï-Ndombe while on the river Kwa early on on Wednesday morning, the office said. It was not clear how many passengers it was carrying. The accident happened in the dark, said the commissioner of the river authority, Ren Maker, adding that it was probably an engine failure. According to Maker, dozens of people jumped into the water when the boat began to sink and were able to save themselves. President Felix Tshisekedi said he was…