BRAZZAVILLE, Republic of the Congo -- Voters in Republic of Congo overwhelmingly approved changes to the constitution that will allow the country's longtime leader to seek another term in office, election officials said Tuesday.

President Denis Sassou N'Guesso was not allowed to seek re-election because the constitution barred any leader from serving for more than two terms. The constitution also said no presidential candidate should be more than 70 years old and Sassou N'Guesso is 71. Sassou N'Guesso called for the referendum, saying he would put the matter to the people. Now with the changes to the constitution, Sassou N'Guesso is eligible to run for another term.

More than 1.2 million people, about 92 per cent of voters, voted on Oct. 25 in favour of the constitutional changes, and nearly 102,000 voted against it, said Interior Minister Raymond Zephirin Mboulou. Turnout for the vote stood at 72 per cent of registered voters, the ministry said.

The opposition, though, had called for their supporters to boycott the vote, and raised questions about the poll, calling it a "constitutional coup."

Voter turnout was lower in the southern districts of Brazzaville, close to opposition strongholds, and also in parts of Pointe-Noire, said government spokesman Thierry Moungalla.

The vote was held peacefully, despite violence during demonstrations the week before that killed at least four people.

Republic of Congo borders the enormous nation known as Congo.

Sassou N'Guesso first served as president from 1979 until a 1992 election defeat. He later seized power in 1997, following a civil war in which his rebel forces ousted the president. He was elected in 2002 and then again in 2009 for what was to be his second and final seven-year term.

The referendum also reduces the presidential mandate from seven to five years and abolishes the death penalty, among other changes.