JOHANNESBURG (AP) — The United States has ordered "non-emergency" government employees and family members to leave Congo as a major election approaches and armed groups remain a concern.

A new advisory urges Americans not to travel to eastern Congo and the Kasai provinces because of conflict.

It says many cities experience sometimes violent demonstrations, and "the government has responded with heavy-handed tactics that have resulted in civilian casualties and arrests."

Congo holds a long-delayed presidential election on Dec. 23. Rights groups and others have reported campaign-related deaths in the past week.

In the capital, Kinshasa, thousands of voting machines were destroyed in a fire that the government said could be criminal in nature. The U.S. notes "extremely limited infrastructure" outside Kinshasa, posing a challenge as Congo uses the machines for the first time.