Turkmen President Kurbanguly Berdymukhamedov has secured a third term in office by winning a widely-expected landslide in Sunday's election, preliminary results showed on Monday.

Berdymukhamedov has won 97.69 percent of the vote with a turnout of 97.27 percent, the Central Election Commission said.

Berdymukhamedov, 59, has run the former Soviet republic of five million people with an iron fist for a decade after succeeding equally autocratic president-for-life Saparmurat Niyazov, who died in 2006.

Eight other candidates ran in the Sunday vote, all of them public servants, managers of state-owned companies or nominees of political parties completely loyal to the government.

Last year, Turkmenistan amended its constitution in a way that could allow Berdymukhamedov to stay in power indefinitely, removing the 70-year age limit for presidential candidates and extending the presidential term to seven years from five.