The National Super Alliance (NASA) opposition coalition late on Friday filed a petition at Kenya's Supreme Court, arguing that last week's presidential poll was "fatally compromised."

"The entire process of tallying recording, transmitting, verifying and confirmation of results was so fundamentally flawed that you cannot talk of any meaningful results," NASA said in a statement.

IIt said votes for the opposition had been removed from some of the ballot box totals after NASA party agents were ordered to leave polling stations. Out of 25,000 results forms, lawyers detected 14,000 of them had errors, the statement added.

Read more: Kenya's next president - The challenges ahead

The coalition's lawyers filed the court papers just 90 minutes ahead of a midnight deadline to challenge the August 8 election. Dozens of opposition supporters gathered outside the court building ahead of the filing.

Kenyatta's sizeable majority

Kenya's election commission insists President Uhuru Kenyatta won a second term by a margin of around 1.4 million votes, achieving 54 percent support. But opposition leader Raila Odinga has repeatedly disputed the results, although he's yet to provide proof.

Odinga had previously claimed that hackers used the identity of a slain election official to manipulate the result against him. He's called for fresh elections.

Even so, international and domestic observers have said the election was largely free and fair.

Seven judges sitting in the Supreme Court have 14 days to hear and determine the petition. They will hear from Kenyatta's Jubilee party and the election commission before making their decision. If they rule in favor of the opposition, Kenyans will again go to the polls within 60 days.

Third election loss

The August 8 vote is the third election that Odinga has lost. In 2007, he disputed the result of an election won by Mwai Kibaki. That vote led to an outbreak of violence that led to 1,200 people being killed. In 2013, Odinga took his complaint against Kenyatta's first election win to the Supreme Court and lost.

Read more: Pressure grows on Kenya's Raila Odinga to calm supporters amid post-election violence

At least 28 people - including children- have been killed in election-related violence since polling day, many of them shot by police. Odinga's supporters, many of whom live in the slums of Nairobi, blocked roads in the city, leading to confrontations with security forces.

mm/sms (AFP, AP, Reuters)