Days after an apparent slip-up let passengers from a Beijing-Vancouver flight enter Canada without clearing customs, three people still haven’t been processed by border security.

Passengers from Air Canada Flight 030 arrived at Vancouver International Airport from China on Sunday, but were directed to the domestic terminal instead of the international one.

A statement from YVR blames the security breach on passengers being led through “a set of doors that were opened in error by an airline employee.”

As of Thursday, the airport still hasn’t released the number of people who managed to enter the country without being processed by Canadian Border Security Agency staff.

Though three still haven’t cleared customs, CBSA said all passengers have been identified and accounted for, and they’re expected to be processed in coming days.

YVR also said it has created a taskforce to review airport procedures to avoid another incident like this in the future.

“Although this kind of error is extremely rare, it happened in our airport and we are committed to helping ensure it does not happen again,” YVR said in a statement.

“We have implemented two actions: increased instructional signs in the area for airline employees, and added security personnel for international flights.”

Sunday’s incident was the first of its kind at YVR, according to the airport.