At least 22 students drowned on Wednesday morning when a boat sank on the Nile River in Sudan, state news agency SUNA reported.A woman also died in the drowning accident that took place at al-Buhaira area, SUNA added.The boat was carrying more than 40 students when it sank.The civil defence forces were sent to the area to search for the bodies of the victims, which have not been recovered.The incident resulted from an engine malfunction, SUNA said.