he Spanish government has declared a state of alert after a strike by air traffic controllers grounded flights, stranding thousands of travellers.

The measure will allow widldcat strikers to be charged with a crime under the military penal code.

It is the first use of the law since it was created after the death of military ruler Gen Francisco Franco in 1975.

About half of the controllers are at their stations but most are refusing to work, in a dispute over working hours.

There are huge crowds of passengers at Spain's airports, many hoping to get away at the start of a national holiday, many of them frustrated and angry, says the BBC's Sarah Rainsford in Madrid.

The army was called in to take charge of the country's air space on Friday, but cannot direct air traffic.

Announcing the state of alert, Deputy Prime Minister Alfredo Perez Rubalcaba said the air traffic controllers were trying to protect "unacceptable privileges".

Spain is engaged in a big austerity drive to cut its budget deficit.

"Our airports are still at a standstill, and according to the Spanish constitution, the government is imposing a state of alert," Mr Rubalcaba said.

"The immediate effect is that the controllers are are now under orders to go back to work and can be charged with a crime under the military penal code if they refuse. The state of alert will initially last for 15 days."

Our correspondent says the controllers could be charged with disobedience, but it is not clear what sentence any conviction would carry.

Some flights were operating to parts of Spain, including the Canary Islands and Majorca but flagship carrier Iberia, and budget airline Ryanair said they were cancelling all their flights until Sunday morning.

Iberia warned people not to travel to airports and said travellers at Spain's airports should leave if they could.

The controllers' unsanctioned action began Friday afternoon in Madrid, with staff calling in sick.

It spread across the nation, forcing travellers to find last-minute hotel rooms or sleep on airport floors. Some passengers were taken by coach to their destinations.

The controllers were already involved in a dispute about their working hours, but were further angered by austerity measures passed by the government on Friday which would partially privatise AENA.

"We have reached our limit mentally with the new decree approved this morning obliging us to work more hours," said Jorge Ontiveros, a spokesman for the Syndicate Union of Air Controllers.

"We took the decision individually, which then spread to other colleagues who stopped work because they cannot carry on like this. In this situation we cannot control planes."

The head of AENA, Juan Ignacio Lema, said the strike was "intolerable", and told the controllers to "stop blackmailing the Spanish people".

Spanish Transport Minister Jose Blanco has also condemned the strike, saying those involved were "using citizens as hostages".

Hundreds of national and international flights have been cancelled across the country, leaving angry passengers left stranded in airports.

Some were left stranded on runways as their planes had to turn back. Others had to travel by bus to regional destinations.

"All flights are blocked, there's a huge lot of people here, sitting around everywhere. Right now everyone is calm, but we don't know what's happening," said one traveller at Barajas airport.

"The captain came out to say Spanish airspace had suddenly shut, with no prior warning," another passenger stuck in a plane at Palma told Spanish radio.

One woman at Barajas airport said it was "a disgrace". "How can a group of people be so selfish as to wreck the plans of so many people?"

Sounds familiar!

The American air traffic controllers went on strike in 1981.  Reagan came in and fired them all.  Then we had a dramatic increase in aircraft crashes in the ensuing years.  Let Spain use that as a lesson.

There is a bit of a difference.  The American air traffic controllers were unionized, whereas Spain's strike is described as "wildcat."

It is the first use of the law since it was created after the death of military ruler Gen Francisco Franco in 1975.


"After the break, Gen. Francisco Franco: Is he still dead?"

My first thought on seeing the headline was that the Spanish had bombed the wrong place by mistake..