An EasyJet flight returned to Belfast International Airport after passengers reported smelling gas shortly after its take-off.
The 9.15am flight from Belfast to Venice returned to the airport following reports of an unusual strong smell at the rear of the cabin.
EasyJet cancelled the Monday flight with the next available plane leaving on Tuesday.
A passenger - who asked not to be named - told the Belfast Telegraph 15 minutes into the flight and over the Isle of Man the pilot announced they were to return to Belfast "for safety checks of a strong smell".
"We were later told it was gas a passenger smelt in row 23," he said
Passengers were taken back to the terminal and told to await further information.
"Staff on board were good though during the events," the passenger added.
An EasyJet spokesman said the flight returned as a precautionary measure due to a "technical issue".
"The captain performed a routine landing in accordance with standard operating procedures," he said.
“Unfortunately due to aircraft availability, we have been required to delay the flight until tomorrow and so we are doing everything possible to minimise the impact of the disruption for our customers including providing hotel rooms and meals for passengers who require them.
“The safety of our passengers and crew is our highest priority and we would like to thank passengers for their patience and understanding and apologise for any inconvenience caused.”