EU observers criticised the Zimbabwe elections for being held on an "un-level playing field" as MDC protested against alleged widespread fraud by the election authority. Picture: Philimon Bulawayo/Reuters

Harare - Zimbabwe's ruling Zanu-PF has attained two-thirds majority in the National Assembly of parliament, which allows the party to change the constitution at will, official results showed.

President Emmerson Mnangagwa's Zanu-PF swept most rural constituencies by large margins while the main opposition Movement for Democratic Change won in urban centres.

European Union observers on Wednesday said Zimbabwe's elections had several problems, including media bias, voter intimidation and mistrust in the electoral commission and questioned delays in releasing the presidential results.

The vote assessment by the EU, which is observing the results for the first time since 2002, is critical in determining whether Zimbabwe can shed its pariah status and return into the international fold, which could help trigger an economic revival.

Earlier on Wednesday, a crowd of around 100 Zimbabwe opposition MDC supporters gathered outside a Harare hotel on Wednesday where election results were being announced but police blocked the entrance to the building, a Reuters witness said.

"You can't rig our election ... this is a military government", the crowd shouted. The situation was under control as police secured the area.