Zimbabwe opposition leader Nelson Chamisa on Friday forcefully rejected the narrow election win of President Emmerson Mnangagwa as fraudulent, calling it a vote "stolen from the people."
The closely-watched elections began with Monday's peaceful vote but turned deadly 48 hours later when the military fired on protesters and six people were killed.
The opposition said it will challenge in court the results of the election, which Mr. Mnangagwa won with just over 50 percent of the vote.
The 40-year-old Mr. Chamisa spoke shortly after three truckloads of riot police with shields and batons tried to disperse dozens of journalists gathered to hear him. With cameras recording their every move the police eventually pulled back, allowing him to give a blistering denunciation of the results.
"We won this election," Chamisa said, declaring "a day of mourning ... for democracy."
He received over 44 percent of the vote but claimed that based on the opposition's own count he won 56 percent. He was asked for evidence but didn't share it, instead saying the electoral commission "didn't want to listen to us."
Chamisa also alleged violence and harassment against his supporters.
Zimbabweans had a subdued reaction to Mnangagwa's win in the country's first vote after the fall of longtime leader Robert Mugabe.
The 75-year-old Mnangagwa, Mr. Mugabe's former enforcer and confidante, said he was "humbled" by the victory and in a Twitter post urged Zimbabweans to stay peaceful.
The president later denounced the police's actions against journalists and defended his victory, saying that "we won the election freely and fairly, and have nothing to hide or fear."
Troops were not visible on Harare's streets but water cannons and police remained present at the headquarters of the main opposition party a day after authorities raided it and made 18 arrests. Chamisa accused them of seeking what he called evidence of vote-rigging.
The week's events left many Zimbabweans with a sense of unease and questions about how different Mnangagwa is from Mugabe, who stepped down in November under military pressure amid a ruling party feud after 37 years in power.
Mnangagwa has tried to recast himself as a voice of change, declaring that the once-prosperous Zimbabwe is "open for business" and inviting the Western election observers who for years had been banned by Mugabe.
If this election is judged credible, it will be a big step toward the lifting of international sanctions on this southern African nation whose economy has long collapsed and whose reputation has suffered after years of repression of the opposition and allegedly rigged votes.
So far international observers have issued mixed reviews, calling Monday's election peaceful and a break from the past but expressing grave concern about the military's "excessive" use of force. They criticized the delay in releasing the results of the presidential vote, saying it raised concerns about possible manipulation.
Some observers from the Commonwealth watched from a rooftop and windows as the riot police dispersed journalists ahead of Chamisa's briefing. Margaret Jay, one of the observers, called it another example of the "excessive use of force in political situations" by Zimbabwean authorities.
Anxious Zimbabweans waited to see what would happen next. In Kuwadzana, a poor suburb outside the capital where groups of youths overnight sang and chanted MDC slogans before results were announced, it was silent.
One street vendor in the capital, Roy Mukwena, said Mnangagwa "won by force. No, I'm not happy, just because these elections were not free and fair."
Some, however, were content to move on and deal with the new leader.
"Yeah, I think he's the right man. Because he has been there for quite some time and he knows where the weaknesses are," said a 29-year-old clerk who gave his name only as Eddy. "He has the experience from ... previous government. So he knows how to maneuver all the problems we have. I just hope he will do well."
This story was reported by The Associated Press.