Air Canada says it is experiencing technical issues causing flight delays for the second time in a week.

The Montreal airline advises travelers to check the status of their flights online as it experiences computer problems.

It is not yet known how many flights are affected.

Air Canada briefly grounded its planes last Thursday, due to an issue with the system it uses to communicate with planes and monitor their performance.

The issue caused delays for nearly half of Air Canada’s flights that day.

The company called last week’s measures “preventive” and said the effects had been limited.