Six flights due to land at Dublin Airport this afternoon have been diverted due to drone sightings on the air field.

Flight operations were suspended for approximately 40 minutes for safety reasons following two confirmed sightings of drones.

Operations were suspended at 2.11pm, and resumed at 2:49pm on runway 28R for departures, and at 2.55pm on Runway 28L for arrivals.

Three inbound flights were diverted to Shannon Airport and three flights were diverted to Belfast Airport.

A number of flights were also forced to divert to Shannon Airport yesterday evening after a drone was spotted at Dublin Airport.

On Twitter, the airport said it is illegal to fly drones within 5km of the airport.

"The safety and security of airport users is daa's key priority at all times & staff at Dublin Airport and An Garda Síochána remain vigilant in relation to drone activity in the vicinity of the airport."

A second incident at Dublin Airport on Friday night remains under investigation.

Operations were suspended for approximately ten minutes on Friday after a drone sighting.

The daa said that as a result, four Ryanair aircraft were diverted last night but were subsequently returned to Dublin.

The Irish Aviation Authority said that any drone flying in the vicinity of an airport is "illegal and extremely dangerous activity".

"These type of reckless actions are extremely disruptive impact airlines, passengers and air traffic control operations," a spokesman for the IAA said.

The statement said the IAA "will be working with daa and An Garda Síochána to ensure appropriate measures are taken against any individuals found to be breaking drone regulations".

Ryanair called for the Minister for Transport to take action to prevent further drone disruption at Dublin Airport.

A spokesperson for Ryanair said: "It is unacceptable that for two days in a row, passengers and flights to/from Dublin were disrupted by apparent drone activity. Yesterday, four Ryanair aircraft and over 700 passengers had their flights diverted to Shannon and Belfast, and again today another four flights and 700 passengers were diverted with thousands more having their flights delayed.

"Such drone disruptions at Ireland's main airport are unacceptable. We are calling on Minister Ryan to take urgent action to protect the country's main airport from repeated disruptions from illegal drone activity."

'Completely unacceptable'

Kevin Byrne, a retired Lieutenant Colonel from the Irish Air Corps and airport safety and security auditor said such drone activity must be taken seriously.

"Anything that interferes with the operation of aircraft in and around airports must be taken very seriously. The thing about drones is they're very small and fly very quickly in relative terms. If you can't see them, they can be a huge hazard to aircraft landing or taking off at an airport, which has enough trouble with weather and wind," he said.

Mr Byrne said that sometimes personnel in air traffic control, pilots themselves, or ground staff can spot the drones.

"If you have to abandon aircraft taking off or landing, it disrupts the entire aviation business and is completely unacceptable in my view."

He said that people flying drones over a certain weight need a permit administered by the Irish Aviation Authority, however, anything interferring with aircraft is a matter for An Garda Síochána to investigate.

"That's quite difficult to see and to; particularly after dark, if drones are flying with an indicated light, it's quite hard to trace where these drones go to and come from, so it's quite a technical matter to police this," he said.