(CNN) -- President Robert Mugabe's ruling ZANU-PF party has lost control of the lower house of parliament, according to results released Wednesday by Zimbabwe's Electoral Commission.
Morgan Tsvangirai has won the presidential election, according to a disputed report from his party.
The results are not yet final, but it appears the opposition Movement for Democratic Change and its allies will secure a majority in Zimbabwe's 210 seat lower house of parliament.
While this gives the MDC significantly more power, certain legislation needs a two-thirds majority to pass Zimbabwe's parliament, which it appears the MDC has not secured.
The electoral commission said it would soon begin releasing results from the upper house, the Senate.
The news came as the main opposition party in Zimbabwe said its leader had won the presidential elections, an assertion the country's information minister disregarded as an attempt to wreak "mayhem and panic."
Despite claims that there will be a runoff to determine the impoverished African nation's next leader -- including a report in Zimbabwe's state-run newspaper -- the MDC says Morgan Tsvangirai won the election flat out.
MDC Secretary-General Tendai Biti called for longtime President Robert Mugabe to step down. Mugabe, who was prime minister before taking the presidential post in 1987, has been in power since Zimbabwe's independence 28 years ago.
"President Morgan Richard Tsvangirai has won this election, not in respect of the gross vote, but in attaining the majority required," Biti said.
Watch why a runoff is likely »
Based on MDC's calculations of the results posted outside polling stations, Biti said Tsvangirai won 50.3 percent while Mugabe received 43.8 percent of the more than 2.3 million votes cast. Mugabe's other challenger, Simba Makoni, received 7 percent of the vote.
It's unclear why Biti's calculations added up to more than 100 percent.
The government hasn't released an official tally, creating confusion and speculation over the results of the election, which represents the toughest challenge to power Mugabe has ever faced.
Though no official results have been released on the presidential vote, Zimbabwean Deputy Information Minister Bright Matonga called MDC's claim of victory "a lot of nonsense" and accused the opposition party of "trying to cause mayhem and panic in Zimbabwe."
"We know what the idea is: They make an announcement; people go in the streets and celebrate," Matonga said. "When there's a new announcement, then the people feel the elections are rigged."
"That's what happened in Kenya," he said.
In Harare, the nation's capital, the mood was calm Wednesday, with no visible signs of celebration or protest. Security forces, including military police, were on the streets but were not an overwhelming presence.
At southern Harare's bustling Mbara market -- where locals said any protest against Mugabe would be most likely to start -- merchants went about their business selling vegetables and cereals, kitchenware and other household goods.
The market is near the spot where Tsvangirai was reported to have been abducted and beaten by government security forces about a year ago. A stall owner said he believes Mugabe's end is near, but also conceded that, in the past, Mugabe had managed to steal elections.
Only Zimbabwe's Electoral Commission can announce the official results of Saturday's presidential election, he said. Those results are slated for release Friday.
See photos from the country's elections »
Mugabe's government blames the delay in releasing the presidential results on logistics, noting that four elections were held simultaneously. Election observers and analysts have raised concerns that Mugabe is using the time to rig the results.
"There is nothing to hide. The results are supposed to be announced within six days after close of voting," Matonga told CNN. "We are in the fourth day so we are within the law."
Matonga told BBC that the MDC's announcement was an attempt to provoke the government and warned that the police and army "will react."
Asked by CNN about that comment, Matonga said he meant the police and army are prepared to "make sure Zimbabweans are protected."
Zimbabwe's state-run newspaper reported Wednesday that a runoff between Mugabe and Tsvangirai is inevitable because neither candidate garnered more than 50 percent of the vote.
Watch the claims and counter-claims »
Biti said the report in The Herald was a government attempt to "prepare members of the public for a runoff." Biti said his party would participate in a runoff vote, but only "under protest."
"It is unlikely that the people's rule will in any way be reversed in that runoff," Biti said. "If anything, there will actually be an embarrassing margin in favor of the opposition in the runoff; there is no question about that."
MDC party officials have wavered in their position since the weekend vote: Biti said Tuesday his party believed it had won enough votes to force a runoff election. On Sunday, MDC declared Tsvangirai the victor based on partial results.
Before the electoral commission announced the parliament results, Biti predicted his party would dominate the lower house of parliament, garnering 99 seats compared to ZANU-PF's 96 seats. He also predicted that an MDC-led coalition would snare 114 seats in the House of Assembly.
A look at the candidates »
Tensions are high in the southern African country that has had only one leader -- Mugabe -- since its independence from Britain in 1980. There are fears a delay in results could lead to violence.
A year after the last presidential election -- which the MDC said was stolen -- the government of Zimbabwe charged Tsvangirai with treason. He was acquitted. The MDC accused Mugabe of trying to eliminate him as a challenger.
Zimbabwe faced international sanctions after the 2002 election, including travel restrictions on Zimbabwean officials.
A hero of the country's civil war against the white Rhodesian government, Mugabe became the country's first black leader in 1980. Nearly three decades later, he has consolidated his rule over all aspects of Zimbabwean life.
His government was once revered for offering citizens some of the best education and health care in Africa, but now schooling is a luxury and Zimbabwe has one of the lowest life expectancies in the world.
Zimbabwe was once known as the breadbasket of southern Africa, but now it is difficult to get even basic food supplies. Inflation has skyrocketed to more than 100,000 percent, while food production and agricultural exports have dropped drastically.
Thousands of Zimbabweans flood neighboring countries to look for jobs.

Part of the economic freefall is traced to Mugabe's land redistribution policies, including his controversial seizure of white-owned farms in 2000. Mugabe gave the land to black Zimbabweans whom he said were cheated under colonial rule. White farmers who resisted were jailed.
Mugabe denies mismanagement and blames his country's woes on the West, saying sanctions have harmed the economy. E-mail to a friend ![]()
Copyright 2008 CNN. All rights reserved.This material may not be published, broadcast, rewritten, or redistributed. Associated Press contributed to this report.
All About Zimbabwe • Robert Mugabe • Morgan Tsvangirai

| Most Viewed | Most Emailed |
| Most Viewed | Most Emailed |