Sudan has declared a state of emergency in areas bordering South Sudan, giving authorities there wide powers of arrest and detention.
A decree carried by the state media today also included the creation of “special tribunals” to try suspects facing terror and customs offences.
The move, together with the arrest yesterday of three foreigners and a South Sudanese in a disputed border area, are signs of spiking tensions along the disputed border, where clashes have raged in recent weeks.
The violence has brought the two nations, already at odds over demarcating the border and dividing oil revenue, to the brink of war.
South Sudan won independence last year as part of a peace deal that ended a long, bloody civil war.