Security staff at Scotland's regional airports from Shetland to Kintyre and Orkney to the Western Isles started a 48-hour strike over pay and conditions.

But only one scheduled service was cancelled, according to operator Highlands and Islands Airports Ltd (HIAL).

The Prospect union says the action was necessary because a six-year-long battle had still not secured equal treatment for the workers from the publicly-owned HIAL.

The union represents more than 120 of the 160 security staff at the 11 HIAL airports which include Dundee, Inverness, Stornoway and Sumburgh.

Union national secretary Alan Denney said: "We put in our claim in October but have yet to receive an offer from the employer in response to this. Not only that, we've seen no evidence to suggest that the claim has been put before the Scottish government, the owners of HIAL."

Once the first 48 hours of strike action has concluded his members would begin a work to contract, including an overtime ban and a ban on rest day working, he said.

A HIAL spokesman said :"We have been working hard throughout the day to ensure that passengers across our airports are not inconvenienced by this industrial action and we would like to thank the many HIAL staff who have volunteered to support this effort.

"We obviously regret that Dundee's scheduled service to Stansted has been suspended for the duration of the strike. However, aside from this, there has been no disruption to passengers, with 10 of our 11 airports operating a normal schedule. "

He thanked passengers for their patience and cooperation and reminded anyone travelling for the duration of the strike action to arrive early for their flight and limit the amount of liquids and luggage they bring to the airport.