The discovery of a suspicious package of tools onboard an Air India flight leaving Toronto earlier this week is now the focus of an international investigation, Canadian police have said.
Peel Regional Police detective Malcolm Bow said officers were pulled off other cases to help with the investigation, which now involves police outside Canada.
Bow, who heads Pearson International Airport's criminal investigations buro, however refused to discuss the scope of the investigation.
He said police are trying to determine whether this involves an aborted act of terrorism or simply an oversight.
Police in a statement had said that a reconstruction of the debris revealed a set of hand tools bound together by tape.
Police had also described the tools as "uniquely packaged" but did not disclose what made it special.
All passengers were released on Tuesday morning after being interviewed overnight by officers.
Flight 188, with 149 passengers and 11 crew members, which left Toronto's Pearson Airport on Monday was an hour into its flight to New Delhi, via Birmingham, England, when a passenger informed the flight crew of a suspicious package in one of the toilets.
Crew members were alerted to the discovery and they told the pilot, who decided to turn back to Toronto. Peel Regional Police searched the aircraft, interviewed passengers and detonated the package.