The United States warned US citizens about possible violence surrounding elections in Ghana next week and urged Americans in the west African nation to take extra security precautions, particularly in the north of the country.

The State Department said the December 7 parliamentary and presidential elections were expected to calm but that past Ghanian polls had been marred by violence that could recur during the upcoming polls.

"Ghana's parliamentary and presidential elections on (December 7) are expected to be generally peaceful, but the potential for politically based incidents of violence is increased," the department said in a statement.

"Northern Ghana in particular has a history of conflict and could be volatile around election time," it said. "American citizens are urged to avoid unnecessary travel to the Tamale municipal area and Yendi District in the Northern Region of Ghana on and immediately after election day. "

The warning also advised US citizens to avoid the town of Bawku in Ghana's Upper West Region and to "exercise extreme caution" in those areas during the election if travel there is required.

An estimated 10 million people are registered to vote in the election in which Ghanaian President John Kufuor is running for a second term against former vice president John Atta Mills.