Abuja, Feb 16 (TIWN / IANS) Nigeria's Electoral Commission has delayed the country's general elections till February 23, making the announcement just five hours before polls were set to open on Saturday.

"After a careful review of the implementation of the logistical and operational plan, and given the determination to hold free, fair and credible elections, the Commission concluded that proceeding with elections as scheduled is not possible," Mahmood Yakubu, Chairman of the Independent National Electoral Commission (INEC), told reporters in Abuja.

He said the difficult decision was needed to ensure a free and fair vote, the BBC reported.

The INEC rescheduled the presidential and parliamentary votes for next Saturday, while governorship, state assembly and federal area council elections for March 9.

The unexpected measure offers "the opportunity to address identified challenges to maintain the quality of our elections", Yakubu said, without elaborating.

More than 84 million Nigerians were supposed to head to the polls for their country's sixth democratic elections in which current President Muhammadu Buhari, 76, is seeking re-election despite fierce criticism of his four-year term. 

His main challenger is former Vice President and businessman Atiku Abubakar, 72.

Nigeria's two key political parties, the ruling All Progressives Congress (APC) and the main opposition People's Democratic Party (PDP), swiftly condemned the move and accused each other of trying to manipulate the vote.

PDP Chairman Uche Secondus said that the postponement was part of an agenda by Buhari to "cling to power". He called on Yakubu to resign immediately, describing the move as "dangerous for our democracy" and "unacceptable".

A statement by Buhari's APC party said the President had "cooperated fully" with the INEC and the decision was "therefore a huge disappointment".

Voters, many of whom had made long journeys to vote, reacted with a mixture of anger, frustration and resignation.

The lead-up to the election was marked by violence, prompting warnings from the British and US governments to say they would deny visas and likely prosecute those found inciting violence during the vote.

Two Nigerian electoral commission offices housing voting materials were burned down within the space of a week.

Authorities bolstered security in much of the country on the eve of the vote, after past elections were also marred by violence, voter intimidation and ballot rigging.

A faction of Boko Haram attacked a state governor's convoy on Tuesday, killing four people. In another incident, 15 people were crushed to death at a ruling party rally in eastern Port Harcourt. On Thursday, 14 sacks of ballot papers were intercepted in Kano state - though the police said they were merely "specimen" papers to educate voters.

This is not the first time presidential elections have been delayed in Nigeria. In 2011 and 2015, they were also postponed for logistical and security issues.