Sudan has declared a state of emergency along its border with South Sudan, in a move that imposes a trade embargo on the South and suspends the constitution, official news agency SUNA said.

President Omar al-Bashir issued a resolution on Sunday declaring the emergency in border districts of South Kordofan state, White Nile and Sennar states, it said.

The measure follows a month of border fighting with South Sudan, which separated last July after a peace deal ended one of Africa's longest civil wars, which killed about two million people between 1983 and 2005.

Zeina Khodr reports from Khartoum, Sudan's capital.