All roads leading to and from the capital of Jonglei State have been closed by security authorities.
Travelers seeking to leave the town were unable to do so, according to sources in Bor. The route via the river to Awerial County, which was used by about a hundred thousand people leaving Jonglei since December, was also closed.
According to a river merchant traveling to Malakal, authorities north of Bor at Shambe prevented them from continuing and made them return to Bor.
The town, located about 180 km (108 miles) north from the capital Juba, was heavily contested in December and January and changed hands four times.
File photo: A South Sudan army soldier near Bor Airport, 25 December 2013 (James Akena/Reuters)