Police in Zimbabwe on Wednesday warned they would arrest persons or groups that release unofficial results of the country's fiercely fought elections.

Traditionally independent local vote-monitoring groups collate parallel tallies as results trickle in from polling stations after counting.

But this year, police warned "all people who may wish to announce the results of elections before ZEC (Zimbabwe Electoral Commission) does so, that they risk being arrested," police spokeswoman Charity Charamba told reporters.

The warning also applies to online publication, she added.

"It does include websites because it still has the same effect.

"The fact that it is on the website still (means) a crime has been committed and if those people are within this country then they will be arrested," she said.

Several online platforms are set to break unofficial results as they come in.

The threat did not seem to deter various organisations and people to post provisional tallies on microblogging site twitter.

Britain's The Guardian and South Africa's Mail & Guardian newspaper, whose publisher is a Zimbabwean national, have set up online voting trends maps for the presidential polls.

Zimbabwe-based pro-democracy group Sokwanele has created an interactive election results map, while the ZimDecides website catalogued problem incidents around the polls.

The police warning followed President Robert Mugabe's threat Sunday to arrest his foe Morgan Tsvangirai if he attempts to declare early victory.

Tsvangirai had earlier told supporters he would announce a tally based on his party's parallel collation if there were delays in the official results.