Harare, Zimbabwe CNN  — 

Zimbabwe’s capital city of Harare resembled a ghost town Thursday, less than 24 hours after six people were killed in clashes between opposition protesters and security forces over the results of Monday’s elections.

Soldiers spent Thursday morning clearing the central business district and warning people to leave by noon. Taxi queues were full of commuters attempting to find a way out.

Shop fronts were locked, and riot police surrounded the headquarters of the opposition Movement for Democratic Change and blocked off nearby streets.

Police arrested 18 people during a raid at the MDC headquarters, Zimbabwe Republic Police spokeswoman Charity Charamba said. The charges were not immediately clear, but Charamba said, in total, officers have taken into custody 26 people suspected of inciting violence during Wednesday’s protests.

In announcing the new death toll – double the three announced Wednesday – Charamba said the army had been deployed in Harare to carry out government orders because “the situation still remains tense and our assessment shows we still require their assistance.”

A man walks past smashed shop windows in Harare on Thursday.

Officials were due to start announcing the results of the presidential election at 10 p.m. (4 p.m. ET), according to Election Commissioner Qhubani Moyo, though it was unclear how long it would take for results to be confirmed.

Officials have so far declared only the results of the parliamentary vote, which gave the ruling Zanu-PF party two-thirds of the seats.

The tense calm in Harare on Thursday marked a stark reversal from the day before, when opposition supporters surged into the streets to protest over claims of vote-rigging and were met with force from police and soldiers.

Tires were set on fire and stones were thrown before security services moved protesters away from a hotel hosting international election monitors.

Police block the road leading to the opposition offices in Harare on Thursday.

The unrest, which has cast a pall over the country’s first election since the toppling of veteran leader Robert Mugabe, prompted statements of concern from the United States, the United Nations and the United Kingdom, all of whom urged restraint.

On Thursday, President Emmerson Mnangagwa, who took over Zanu-PF from Mugabe, called for an independent investigation into the violence. He said he had reached out to the opposition to open a dialogue about how to quell tensions, but his presidential opponent, Nelson Chamisa, refuted that claim.

“In any event, reaching out on the basis of fudged elections is not acceptable,” Chamisa told CNN. “You can’t rig an election or manipulate an election because you control that and you want to then use that as the basis of engagement. That’s deception.”

Opposition supporters react after police fire tear gas in Harare on Wednesday.

Chamisa’s spokesman has also said that protesters were not violent Wednesday and that the deployment of soldiers was unnecessary.

The government claims the MDC was irresponsible in calling for protests, but Chamisa said, “Well, it’s not irresponsible to respect the constitution, is it? The constitution gives the right to demonstrate and the right to protest.”

Freddie, a flower seller in Africa Union Square, told CNN the current scenes in the capital contrasted sharply with the jubilation witnessed at the news of Mugabe’s resignation.

Soldiers in balaclavas shout orders to street vendors in Copacabana market Thursday.

“We were so happy then, but now we are nervous – we don’t know what’s going to happen. It is very different now,” he said.

As police surrounded the MDC building Thursday, opposition party spokesman Nkululeko Sibanda insisted his organization was well set for victory.

“We have collated results from the 80% of the polling stations that we’re allowed to do so and we’re very clear that we’re going to win,” he said. “There is no way with the 20% they are going to win. If the result is such that if we didn’t win, then certainly it’s not the reflection of what the people of Zimbabwe did on the 30th.”

A Zimbabwean soldier beats a man in a street of Harare on Wednesday, August 1.

Zimbabwe is eager to ensure that elections are considered free and fair to lure back foreign investment and resuscitate the country’s economy.

While Zanu-PF won a sweeping majority in parliament, according to electoral officials, the results prompted accusations from the opposition that the polls had been rigged.

The MDC has insisted that Chamisa, who took over the party’s leadership following the death of founder and longtime Mugabe rival Morgan Tsvangirai in February, won the presidential election.

Zimbabwe police patrol the streets of Harare on Thursday.

Asked how he’s so confident the vote was manipulated when results haven’t been announced, Chamisa told CNN that the MDC has its own “intelligence” and its agents have told him the results of the tallies. The delay in releasing the official results is evidence of “an attempt to try and massage the outcome.”

He said he would not accept any declaration that Mnangagwa won.

“We can’t accept a fallacy, fiction and falsehoods,” Chamisa said. “No amount of fidgeting with the results is going to alter the will of the people of Zimbabwe. People want change and that change we are ready to deliver.”

International concern

Mnangagwa described Wednesday’s bloodshed as a “tragedy” and urged the country’s political leaders to “seek peace and pursue it.”

Earlier he had blamed the MDC for the unrest, saying its party leaders had abetted “acts of political violence.”

Supporters of the opposition party protest in Harare on Wednesday.

International monitors have called on the electoral commission to promptly publish the results of the closely fought presidential race.

Partial results of the parliamentary elections gave Zanu-PF 140 seats to the MDC alliance’s 58, officials said Wednesday. There are 210 seats in the National Assembly’s lower house.

The electoral commission later tweeted it had announced the results of 207 constituencies, without giving further details.

“The results of the remaining 3 constituencies and presidential results will be announced within 5 days from polling day as stipulated by the law,” it added.

On Thursday morning, the commission’s website was down. Reports said it had been hacked during the night, with pictures of injured protesters posted on it.

Severe challenges

Mnangagwa, 75, took power after helping orchestrate a de facto coup against Mugabe in November. He has tried to rebrand Zanu-PF, pledging to heal divisions and rebuild the country.

Known as “the crocodile” for his cunning and longevity, he is still viewed as Mugabe’s man because he worked so closely with the former leader for more than 40 years, first as his special assistant during the 1977 liberation war, and later as security minister and justice minister.

Mnangagwa addresses a meeting of farmers on July 21 ahead of the election.

Chamisa – the country’s youngest-ever presidential candidate – has appealed to younger voters with promises of electoral reform, tax cuts and jobs.

While his message may strike a chord, he does not have as much backing as Mnangagwa from the security forces and military, which oversaw Mugabe’s departure.

Zimbabwe faces severe challenges as it seeks to recover from an economic crisis dating back to Mugabe’s rule.

Journalist Columbus Mavhunga and CNN’s David McKenzie and Brent Swails reported from Harare, and James Masters wrote from London. CNN’s Eliott C. McLaughlin, Bard Wilkinson and Lauren Kent also contributed to this report.