The U.N. secretary-general has urged African leaders not to cling to power.

Ban Ki-moon said that undemocratic constitutional changes and legal loopholes should never be used by leaders to stay in office.

Speaking at the summit of the 54-nation African Union, Ban urged African leaders to listen to their people saying that modern leaders cannot ignore the wishes of those they represent.

Some African leaders have been in power for decades after altering their constitutions to extend their tenure in office. Recently Congo passed a law that required a census before the 2016 elections. The law sparked off violent protests in which dozens were killed as critics accused President Joseph Kabila, who has been president since 2001, of attempting to prolong his stay in office.