PARIS — Applause, cheers and whoops of joy rang out at airports around the world Tuesday as airplanes gradually took to the skies after five days of being grounded by a volcanic ash cloud that has devastated European travel.

But weary passengers might have to tamper their enthusiasm. Only limited flights were allowed to resume at some European airports and U.K. authorities said London airports would remained closed for at least another day due to new danger from the invisible ash cloud.

And with over 95,000 flights canceled in the last week alone, airlines face the enormous task of working through the backlog to get passengers where they want to go — a challenge that certainly will take days.

Still, in airport hubs that have been cauldrons of anxiety, anger and sleep deprivation, Tuesday marked a day of collective relief.

The boards at Paris' Charles de Gaulle Airport announcing long-distance flights filled up with white "on time" signs Tuesday and the first commercial flight out since Thursday left for New York's John F. Kennedy Airport.