The Spanish government today called on political parties to isolate the Basque separatist group ETA after the guerrillas declared an end to their 14-month-old cease-fire. The government warned that the armed group, fighting for an independent Basque state since the late 1960s, was weakened but still dangerous.

Industry Minister Josep Pique, the government's spokesman, said there would be no new talks with ETA after its announcement Sunday that it was resuming its armed struggle. "Violence will lead nowhere, they have to understand that," Pique told state-run National Radio.

Instead, he said, the government needed to intensify talks with Spain's democratic political parties to ensure a united front against ETA, or Basque Homeland and Liberty, which has been blamed for the deaths of 800 people in its three-decade fight.

In a statement Sunday, ETA accused the government of blocking any discussion of Basque independence, and said it would give its fighters new orders Friday, the day the unilateral cease-fire officially ends.

As Spain braced for a possible resumption of violence, police in the Basque region reportedly beefed up security.

Newspaper editorialists condemned ETA's move, noting the contrast with progress toward peace in Northern Ireland, where Protestants and Roman Catholics set up a new joint government today after decades of sectarian killings.

Socialist opposition leader Joaquin Almunia dropped his criticism of the government's hard-line tactics toward ETA and joined Prime Minister Jose Maria Aznar in pointing the finger of blame solely at the guerrillas.

Aznar, who had hoped the peace process would be intact when he faces Almunia in next spring's general elections, said terrorism had become an "anachronism" in Europe. "Any act of terrorism is . . . . a pathetic and frustrated attempt to impose injustice," he told reporters.

Interior Minister Jaime Mayor Oreja said ETA was not as strong as in the past. At the height of its violent campaign, ETA killed 118 people in 1980 alone. But by the time it called its cease-fire in September 1998, the group had dwindled to a few dozen fighters and it was carrying out only sporadic attacks.

"ETA was in a bad way a year and a half ago and it's not much better now," Mayor Oreja told radio station Onda Cero. However, he warned, "as long as they are able to kill, I will not use the word 'weak.' "