Striking Spain air traffic controllers return to work
Most of Spain's air traffic controllers have returned to work and airspace has reopened, after a walkout grounded flights and stranded thousands.
The government had imposed emergency measures not seen since military rule ended in 1975, threatening to prosecute workers who refused to end the strike.
Officials said 250,000 people had been affected by the walkout, amid a long-running dispute about working hours.
Ministers warned that disruption could continue for up to 48 hours.
Works minister Jose Blanco said the situation was improving, and all Spanish airspace had now reopened.
But he added: "Normality will take some time, between 24 and 48 hours, if the controllers return to work as they must."
Airport authority AENA said some flights had already begun to leave.
But most airlines have already cancelled the majority of their flights in and out of the country until Sunday morning.
The BBC's Sarah Rainsford in Madrid says there is a long backlog of flights, and crowds of frustrated passengers still do not know how or when they will get home.
The strike came as many Spaniards were preparing to enjoy a long holiday weekend.
The army was called in to take charge of the country's airspace on Friday, but they do not have the training to direct air traffic.
Announcing the first state of alert since the end of military rule in 1975, Deputy Prime Minister Alfredo Perez Rubalcaba said the air traffic controllers were trying to protect "unacceptable privileges".
"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 were facing a charge of disobedience, but it is not clear what sentence any conviction would carry.
But the threat of prosecution appeared to have been enough to persuade the controllers to return to work, our correspondent adds.
By late afternoon, officials said 283 of 296 controllers had turned up for their shifts, with just 13 absent.
National carrier Iberia, which had previously cancelled all of Saturday's flights, said it hoped to start long-haul flights mainly to Latin America overnight.
Flights to and from places including the Canary Islands and Majorca were quick to resume after the strike came to a halt.
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 as Spain tries to cut its budget deficit.
"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."