File picture: Matthews Baloyi/Africa News Agency (ANA)

Harare - The Zimbabwe Election Commission is preparing to release results of the contested presidential election from 10pm (20.00 GMT) on Thursday, a spokesman told AFP.

"The presidential election results will start to be announced around 10 pm," ZEC commissioner Qhubani Moyo said.

"We are hopeful that all of them will be announced today."

Zimbabwe has been on edge awaiting the results of its historic presidential election after troops opened fire on protests against alleged electoral fraud, denting hopes of a new era for the country following the ousting of Robert Mugabe.

The government late Wednesday vowed to enforce a security crackdown to prevent further unrest after the army opened fire to disperse opposition protests in Harare, leaving at least three people dead.

Monday's polls -- the first since autocratic president Mugabe was forced out by a brief military takeover in November -- had been meant to turn the page on years of violence-marred elections and brutal repression of dissent.