Around 200 people, presumably illegal migrants to Saudi Arabia, drowned when their vessel caught fire in the Red Sea off Sudan late on Tuesday, Sudanese media reported.
A total of 197 people died in the incident, the Sudanese Media Centre news agency said.
Three people were rescued, and a search for possible survivors was launched, officials said.
The boat was flying a Cuban flag. Four Yemeni nationals, suspected to be owners of the boat, have been detained.
In another incident, a second boat with 247 migrants onboard - mostly nationals of Somalia, Eritrea, Chad, and Nigeria - was detained while travelling in the same sea area.