Officials say 92 percent of voters in a Congo Republic referendum want President President Denis Sassou Nguesso to run for a consecutive third presidential term, but four people died when security forces fired on protesters, Retuers reports in BusinessDayLive.

He is the latest African president to try and hold onto power by changing the constitution. Similar efforts by other African leaders have provoked violence and wars.

Sassou Nguesso has ruled the oil-producing nation for 31 of the last 36 years and the constitutional change will let him serve another seven if he wins the next election, planned for 2016.

The Republic of the Congo, also known as Congo Republic, West Congo, or Congo-Brazzaville, had a population of 4.448 million in 2013, according to World Bank.

Turnout at the referendum Sunday was 72 percent, according to the electoral commission radio announcement.

More than 1.2-million people voted in for the change, while nearly 102,000 rejected it, the electoral commission said.

The opposition said turnout was low and boycotted the poll. A senior opposition leader said it should be annulled.

Sassou Nguesso ruled the Central African country from 1979 until 1992, when he was defeated in a presidential election. His rule resumed five years later after his forces defeated the then-president in a civil war.

Under the current constitution, the president could not seek re-election because he has already served two terms and over the age of 70, BBC reported.

Sassou Nguesso, 71, is one of Africa’s longest-serving rulers. After losing the 1992 election, he returned as president in 1997 following a civil war, and has since won two elections.

He is now nearing the end of his second seven-year term since 1997.

Tens of thousands of people took part in a peaceful demonstration against the referendum in September, BBC reported.

You can check out a list of longest-serving African dictators in this AFKInsider report.