BEIJING - China on Tuesday urged Sudan and South Sudan to maintain calm and exercise restraint to prevent current tensions from escalating.

"We have noticed relevant reports," Foreign Ministry spokesman Hong Lei said at a regular press briefing when commenting on reports that Sudanese President Omar al-Bashir suspended a planned visit to South Sudan because of the latter's attacks on Sudan's oil area.

Hong called on the two sides to properly handle disputes through negotiations.

The Sudanese army said Monday that limited clashes took place between it and South Sudan's army in South Kordofan, which lies on the border between the two countries.

The clashes between Sudan and South Sudan came at a time when the two sides have shown signs of understanding, as they have agreed to convene a summit for the two countries' presidents on April 3 in Juba to discuss outstanding issues.

South Sudan President Salva Kiir Mayardit announced Monday that his forces had entered Higlieg, Sudan's strategic oil area, and, in response, the Sudanese government threatened to halt dialogue with South Sudan.