Nairobi (AFP) - On a Sunday morning in September three young women were killed by officers at the main police station in Kenya's second city -- but that's the only fact beyond doubt in a case that activists say is further evidence of a police force gone rogue.
In the official version of events, police thwarted an attempted terrorist attack on September 11 when the women -- who they say recently pledged allegiance to the Islamic State group -- entered Mombasa Central Police Station armed with a knife, a petrol bomb and a suicide vest.
It said vigilant officers fired on them while one of the attackers was burnt almost beyond recognition by her incendiary device. Subsequently, seven alleged conspirators have been rounded up.
But two separate human rights groups working independently pieced together a different story.
In actual fact, they said, the three girls went to report a stolen phone, fought back when male officers attempted to forcibly remove the hijab of one, and were all then shot dead and at least one set alight to lend credence to the cover-up story.
There were no weapons, they say, no suicide vest, no terrorist plot and no conspirators.
The contradictory reports have triggered a "full-scale investigation" by the Independent Policing Oversight Authority, said the watchdog's chairman Macharia Njeru. The investigation can lead to criminal prosecution, disciplinary action or exoneration for the officers involved.
- 'Unanswered questions' -
"Police in Kenya concoct stories to justify killing people," said Otsieno Namwaya, Africa researcher at Human Rights Watch, a New York-based advocacy organisation. "They use 'terrorism' to justify all manner of killings."
In this case, Namwaya said, "There are so many unanswered questions. The police look like they are struggling to cook a story."
That impression was strengthened by two ugly video clips filmed on the day.
One clip shows two of the girls lying on the ground outside the police station. They are Maimuna Abdirahman Hussein, 22, and Tasmin Abdullah Farah, the alleged "mastermind". One sits with her right arm in the air before collapsing next to the prone body beside her and rolling onto her back.
Over the next two minutes at least two armed officers take turns firing seven shots at the girls.
The second clip, allegedly filmed inside the police station, shows a horribly burned woman -- Ramla Abdirahman Hussein, aged 19 and the sister of Maimuna -- lying on the floor, moaning as police question her.
Khelef Khalifa, chairman of the Mombasa-based Muslims for Human Rights (MUHURI) group, said the call to prayer that can be heard in the clip as the woman lay dying shows she was left without medical assistance for two hours.
"We see this as extra-judicial killing," he said. "A dead person doesn't talk."
- 'This is a cover-up' -
Khalifa pointed out that if the young women were terrorists as police claim, they could have been arrested instead. He also questioned the plausibility of the alleged plot.
"It is mind-boggling! Three ladies go and attack a police station with a knife? These girls cannot even steal in my house let alone a police station," he said.
On Friday a government pathologist postponed indefinitely a scheduled postmortem of the two sisters, and the following day the bodies were buried. "In Kenya, you cannot take a death without autopsy anywhere in a court of law. This is a cover-up," said Khalifa.
Kenyan police are routinely accused of running death squads and killing suspects as well as those with whom they have disputes.
Four police officers were charged with murder earlier this year after lawyer Willie Kimani, his client and driver were tortured, murdered and dumped in a Nairobi river after a long-running legal battle stemming from an assault claim against the senior officer.
Police have made various allegations since the Mombasa incident, and neither the bullet-proof nor suicide vests the women allegedly wore, nor the knife, have been produced, while a handwritten note declaring their allegiance to Islamic State has yet to be verified.
After the attack was reported an IS-linked website claimed its "supporters" carried out the attack.
For human rights activists the contradictions and outlandish allegations are all too familiar. "It can be shocking to someone who doesn't know what police do," said Namwaya, "but this is typical."