Seven suspects arrested while taking photographs of planes taking off and landing at Wilson Airport in Nairobi were on Monday interrogated for the third consecutive day.
The men were questioned at the Anti-Terrorism Police Unit headquarters where they were taken after their arrest on Saturday.
Nairobi deputy police boss Moses Ombati said that investigations were intended to establish the motive of the suspects.
Although the law stipulates that suspects should be arraigned in court not later than 24 hours after arrest, police could not say why the seven had been detained for that long.
Claimed to be tourists
Police said the suspects, who include two from neighbouring Somalia, claimed to be tourists who were viewing wildlife.
But their mobile phones had allegedly captured images of planes.
They are also said to have taken pictures of the airport.
Upon their arrest, a laptop, camera, binoculars, ipads and pepper spray were recovered.
The pick-up they had parked near Mitumba slums was also seized and towed to Lang’ata Police Station.
High security alert
Their arrest comes at a time when Kenya has been put on high security alert following threats by Al-Shabaab to launch attacks in revenge for military incursion into Somalia.
The terror group has threatened to bring down Nairobi’s storey buildings in two weeks.
Elsewhere, the proprietor of Kalita Bus Transporters Patrick Lucky was on Friday questioned by Uganda’s head of CID Grace Akullo after a suspected terrorist entered Uganda aboard one of the company’s buses.
The conductor of the bus is said to be missing.