British Airways has cancelled more than 400 flights due to a drop in passenger numbers caused by Covid-19, the airline has announced.
Most of the cancellations are for short-haul flights between Heathrow and Italy, France, Austria, Belgium, Germany, Ireland and Switzerland.
It has also grounded 24 flights between Heathrow and New York's JFK airport.
A British Airways spokesman said: "To match reduced demand due to the continuing coronavirus issue, we are merging a number of flights between March 16 and March 28.
"We will be contacting customers on cancelled flights so we can discuss their travel options, including re-booking on to other carriers where possible, full refunds, or booking with BA for a later date of travel."
Airlines operating in the European Union are not required to pay compensation for flight cancellations if passengers are told at least 14 days before they were due to travel.
British Airways told the PA news agency that pilots and cabin crew due to work on the affected flights would still be paid.
The airline has already suspended its flights serving mainland China and reduced the frequency of flights to northern Italy and Singapore.
It also announced on Monday that it has waived its fees for customers who book flights in the next two weeks, but later decide not to travel.
Ryanair said it is cancelling up to one in four flights on some of its routes, particularly those serving Italian airports.
The reduced schedule will operate from March 17 until April 8, following a "significant drop in bookings" over the period, according to the carrier.
The Dublin-based airline said it is taking a series of measures in response to the coronavirus outbreak.
These include "rolling schedule cuts", allocating leave or paid leave to pilots and cabin crew, working with suppliers to cut costs and freezing recruitment, promotion and pay across its network.
Ryanair insisted it is "one of the strongest airlines in the industry" but predicted that Covid-19 "will result in further EU airline failures over the coming weeks".
Ryanair Group chief executive Michael O'Leary said: "This is a time for calm. We will make sensible cuts to our schedules over the coming weeks to reflect weaker bookings and changing travel patterns."
EasyJet announced last week that it was cancelling some flights because of the coronavirus.
The International Air Transport Association (Iata) warned last month that airlines could lose 29.3 billion US dollars (£22.7 billion) this year due to the outbreak.
The trade association, which represents airlines, has called for regulators to relax rules on take-off and departure slots amid the drop in demand.
Allocation of slots at UK airports is governed by the European Union, which has a so-called "use it or lose it" rule, which means airlines must use 80% of their slots or risk losing them.
Iata claimed it would be "inappropriate" to apply the rule in summer 2020, to allow airlines to adjust their schedules in response to the "extraordinary demand developments" caused by Covid-19.
In response, trade body Airports Council International Europe said the virus is "significantly impacting Europe's airports".
It added: "We support a partial relaxation of EU rules governing the use of airport slots use, but do not consider at the moment that a blanket relaxation for all air routes is justified."