LILONGWE/BLANTYRE (Reuters) - President Joyce Banda on Saturday cancelled Malawi's elections citing fraud and "rampant irregularities" in a decision that triggered protests and was challenged by the national electoral authority and a political rival.
Banda, who had been standing for re-election, ordered a new vote within 90 days but said she would no longer be a candidate to guarantee a credible outcome.
Malawi's Electoral Commission (MEC) and one of her main rivals for the presidency who had been leading in the vote count so far contested her annulment announcement, saying she did not have the constitutional power to cancel the elections.
Her decision led to protests at Limbe outside the commercial hub of Blantyre, where demonstrators smashed shops, police said.
The political crisis broke out four days after a problem-plagued vote in the aid-dependent country, where Banda, southern Africa's first elected female head of state, has seen her popularity eroded by a corruption scandal.
"I, Dr. Joyce Banda, President of the Republic of Malawi, in exercise of the powers conferred by section 88 (2) of the Constitution, hereby issue this Proclamation nullifying all on-going processes in relation to the 2014 Tripartite Elections," Banda said in her broadcast.
She cited "fraudulent and rampant irregularities" and ordered that voting be repeated within 90 days.
Shortly before Banda's announcement, the electoral commission released preliminary results showing opposition Democratic Progressive Party candidate Peter Mutharika leading with 42 percent of the vote, followed by Banda with 23 percent. This was based on 30 percent of the total votes counted.
"There is no legal basis for stopping the election. We have become a laughing stock and the sooner it ends, the better for us," Mutharika told a news conference, as his supporters took to the streets in Limbe.
"I appeal to the President to ask people to be calm and I hope she abandons the path she is taking because we don't need to take this country on the path of violence," Mutharika added.
Malawi Electoral Commission (MEC) chairman Maxon Mbendera also challenged the annulment, saying only the electoral authority had the legal power to do this.
Banda said she would not participate as a presidential candidate in the election re-run.
"I have done this to allow that Malawians are given an opportunity to freely and fairly express their will in choosing their leaders in a free, fair, transparent and credible manner," she said.
Tuesday's poll had been plagued by problems from the outset, with voting materials turning up hours late and ballot papers being sent to the wrong end of the country, infuriating voters.
Organizers had to extend voting in some urban areas into a second day and initial counting was held up by a lack of lighting and generators at polling stations.
Banda enjoyed huge goodwill when she came to power two years ago, but her popularity waned after she was forced to impose austerity measures, including a devaluation, to stabilize the economy.
Her administration was hit by a $15 million corruption scandal, dubbed 'Cashgate', after large amounts of cash were discovered in the car of a senior government official.
(Fixes typo in dateline)
Writing by Zandi Shabalala; Editing by Pascal Fletcher and Angus MacSwan