Officials at Pearson Airport stepped up security after a flaming SUV drove into a Scotland airport terminal building's entrance Saturday.

A spokesman for the Greater Toronto Airports Authority said Sunday that Pearson staff are conducting a full review of security procedures.

He also says security staff at Pearson had to make few adjustments because security was already stepped up for the Canada Day weekend.

Passengers aren't expected to experience delays or notice anything unusual.

The apparent attack at Glasgow Airport came after a pair of car bombs were found and defused in London on Friday.

British police also conducted a controlled explosion Sunday on a car found outside a Scottish hospital treating one of the terror suspects connected with the two incidents.

Four suspects were in police custody Sunday and a fifth man, who was in critical condition, remained under guard in the hospital.

Scotland's Justice Secretary Kenny MacAskill said Sunday the perpetrators were not "born and bred here,'' effectively putting to rest any speculation that the attacks were a home-grown terror plot.

Witnesses at the airport said two men drove their burning Jeep Cherokee at full speed through security barriers and into the glass doors at the entrance of the terminal.

Both men, one of them on fire, then exited the vehicle, witnesses said.

The recent incidents have raised fears that the type of car bomb attack that has become commonplace in Iraq has now reached European shores.

The U.K. remained at its highest terrorist alert on Sunday.

With files from The Associated Press and The Canadian Press