ETA announced last week that its 14-month cease-fire would end on Friday because the political process had gone nowhere.

In dozens of cities and towns across Spain and in south-west France, people gathered to protest against ETA's decision on Friday.

They stood silently in the streets of the Basque region at noon local time (1100 GMT), praying for peace to continue.

Izazkun Rekalde, wife of a former ETA leader, in a French peace protest

Many of the demonstrators were pro-Basque, but anti-ETA.

Among them stood members of ETA's political wing, Herri Batasuna, holding placards calling for the release of jailed separatist fighters.

Protests were also held in Madrid, Barcelona, Seville and Bayonne in south-west France - one of the biggest outpourings of anti-ETA sentiment since mass demonstrations in 1997 after the killing of Basque town councillor Miguel Angel Blanco.

"What ETA has to do now is abandon its armed struggle for good and turn the page on this chapter," Spanish government spokesman Josep Pique said.

Security stepped up

ETA - whose initials stand for Basque Homeland and Freedom - has been blamed for nearly 800 deaths in its 30-year campaign to create an independent Basque state in northern Spain and south-western France.

Police have resurrected security measures that were in place before ETA declared its cease-fire in September 1998.

Protection for politicians considered likely targets has been reinstated.

Police throughout Spain distributed photographs of suspected guerrillas believed to have re-entered the country from hiding places in France.

Surveillance on the Spanish-French border has also been intensified.

'Armed blackmail'

Meanwhile, moderate Basque nationalists - who helped negotiate last year's truce - signed a fresh agreement with ETA's political wing reaffirming their pledge to seek independence.

That drew angry accusations from the government that they were selling out to ETA.

Education Minister Mariano Rajoy accused ETA of armed blackmail.

"The Spanish people will never accept what ETA is trying to force on them," he told state radio.

While no attacks have been reported, Basque authorities have warned that ETA could attack as early as this weekend.