Central African Republic's National Election Authority and the United Nations say voting on a constitutional referendum has been extended in areas where violence kept people at home.

Violence on Sunday prevented many from voting on a referendum seen as a test of whether national elections can take place at the end of the month.

The vote was held Monday in the PK5 neighborhood of the capital, Bangui, where at least two people were killed Sunday. Officials said the vote would be extended to the northern town of Kaga-Bandoro Tuesday.

U.N. peacekeeping chief Herve Ladsous said Monday the vote is also extended in Birao, Bossangoa and Ndele. It is unclear how long the vote will be extended.

Presidential elections are scheduled for Dec. 27 and have already been delayed several times.