TORONTO -- Federal transportation investigators say they are unable to identify an airborne object that caused a Toronto-bound plane to take evasive manoeuvres that left two flight attendants with minor injuries.

A Porter Airlines flight en route from Ottawa to Toronto on Nov. 14 narrowly avoided a mid-flight collision above Lake Ontario with what flight crew said may have been a drone.

The Transportation Safety Board says it has closed its investigation into the incident saying that the description and size of the object doesn't match that of a drone.

They also say the incident occurred too far from shore and too high for it to be a drone.

The Dash 8 aircraft with 54 passengers was flying at just under 3,000 metres over Lake Ontario at 7:30 a.m. and was about 55 kilometres from Toronto's island airport when the near miss occurred.

The TSB says the incident has been classified as a near miss with an unidentified airborne object and says it will not file a full, public report.

Porter previously said its two flight attendants, who were in the process of securing the cabin for landing and weren't in their seats, were pitched about the cabin, but continued with their duties.

No passengers were injured during the flight and the plane landed normally.