At least seven people were killed on Sunday while 21 others were injured after an attack carried out by armed men from Chad at Ngbengbere village near the Central African Republic's border with Chad, local sources said.

"They came on board seven vehicles and 30 motorcycles. They burnt everything in the village and killed seven people while injuring 21 others. They then returned to Chad," Max Bataillon, a deputy mayor for neighboring town of Paoua told Xinhua on phone.

The attack comes after last Friday's withdrawal from Bangui of 200 Chadian soldiers from the International Support Mission for Central African Republic, MISCA.

This followed the decision by N'Djamena authorities to withdraw their troops from the African force charged with the responsibility of restoring peace and security in Central African Republic.

Chad had 850 soldiers out of the 6,000 MISCA soldiers. They had been accused of complicity with ex-Seleka rebels who overthrew Francois Bozize in March 2013.

The porosity between the Central African Republic-Chad border allows armed groups to move freely.

"We urge the transition authorities to secure the border between the two countries to stop armed groups from Chad from entering the country and attacking the population," an NGO official from Ngbengbere, Guy Motouri, said.

A source from the public security ministry said the Bangui authorities were planing to issue a statement on the attack which they considered as "an act of provocation."