Thiruvananthapuram, March 22 (IANS) A day after a cocktail of explosives was found in the cargo section of a Kingfisher plane here, police Monday were still clueless as to how it reached the aircraft despite multi-layered security checks.

Kerala Director General of Police Jacob Punnoose said the probe is on but there has been no breakthrough yet.

'There were 27 passengers on board. We are yet to identify all the passengers because these days booking is done through the internet and hence the delay in identifying them. The copies of the video footage are also being collated from Bangalore and from here,' said Punnoose.

The Kingfisher plane from Bangalore landed here at 8.25 a.m. A Central Industrial Security Force (CISF) official reportedly discovered crude explosives, a cocktail of sulphur, potassium chlorate and aluminium powder, in the cargo hold.

The discovery triggered panic alarms in Bangalore and Thiruvananthapuram, leading to a high-level investigation on how it got past the many layers of security.

Punnoose said that a team of Kerala police who went to Bangalore airport Sunday night has since returned.

'Our officials are leaving no stone unturned and all possible leads are being examined,' Punnoose said.