A strike by Irish air traffic controllers will disrupt flights in Ireland for up to four hours Wednesday, the Irish Aviation Authority (IAA) said.

The industrial action by labour union IMPACT "will involve work stoppages between 14.00 and 18.00 in Dublin, Cork and Shannon Airports and will disrupt services at all airports," the IAA said in a statement.

The Authority warned the union against the action, urging it to defer a six percent pay claim, pay "a pension contribution like everyone else in the public service" and return to normal working.

The IAA said the controllers had a total pay package of 160,000 euros (228,000 dollars) a year.

Irish no-frills airline Ryanair said it was cancelling 48 flights affecting over 6,000 passengers, calling the strike "industrial action by overpaid and underworked Air Traffic Controllers."

"Passengers affected by these cancellations should seek compensation from IMPACT General Secretary Peter McLoone," it said, giving email and telephone contact details.