TORONTO -- Service on the UP Express has resumed after an earlier signal problem forced the route to be suspended. 

The transit service said GO shuttle buses were made available to those travelling to and from Union Station and Pearson Airport during the closure.

Anyone who used the UP Express for non-airport travel was being asked to consider taking the TTC at Bloor or Weston during the closure.

The signal issue also caused issues on GO Transit's Kitchener Line this morning. GO Transit also reported delays on the Lakeshore West and Lakeshore East lines due to signal issues.

It is not clear what caused the signal problem but service resumed just after 11:30 a.m.