Hundreds of South Sudanese civilians drowned in the Nile while fleeing fighting between government and rebel forces in the northern town of Malakal, regional broadcaster Radio Tamazuj reported Tuesday.
The BBC cited an army spokesman as putting the number of victims in Sunday's accident at more than 200, dpa reported.
Local official Majok James Chol told Radio Tamazuj that panic had swept Malakal owing to rumours that forces loyal to rebel leader Riek Machar were about to attack it.
Hundreds of people thronged a boat that could only accommodate up to 80 passengers, according to the report.
"People grabbed the sides, but when the boat capsized, only two people and the boat driver managed to reach the banks alive," Chol was quoted as saying. "This part of the Nile is wide and deep and has a strong current."
The victims reportedly included children.