Continuing police repression has inflamed the Basque region in the past five days to the point of rebellion, posing a serious political problem for King Juan Carlos and Premier Adolfo Suarez on the eve of Vice President Walter Mondale's official visit to Spain.

Mondale, who is to arrive here Tuesday, from Lisbon for an overnight visit, will not witness any of the violence, which started Thursday in the northern provinces of Alava, Guipuzcua, Navarre and Vizcaya.

Since then, reinformed police and Civil Guard detachments have used all weapons at their disposal to put down regional rallies to ask amnesty for political prisoners, civil rights and self-rule.

Police clashed again with thousands of demonstrators in the region, which was paralyzed by a general strike involving more than half a million workers. The strikers took to the street in Bilbao and Pamplona to protest the crackdown, which equaled the use of force against Basques during the dictatorship of Generalissimo Francisco Franco. Sympathy strikes erupted in Madrid and Barcelona.

There were no immediate reports of injuries today. Five Basque demonstrators have died as a result of clashes, three from police gunfire. At least 57, including 24 police officers, were reported seriously wounded.

Like thousands of Basques, the bishop of Pamplona, Jose Mendez, criticized the Suarez government yesterday for unleashing police in the region. "Police must be taken off the streets," said the bishop. "They are the cause of the violent confrontations."

Police trampled flowers placed on a Pamplona street in memory of a 28-year-old man shot and killed by public order forces Friday. Eyewitnesses said that the man was shot after being knocked to the ground.

Basque priests, moderate political leaders and liberal Madrid newspapers have joined the chorus of criticism. They stressed that after the government established a policy of tolerance four months ago, Baque political demonstrations and regional demands for amnesty and self-rule have gone on without incident.

The Interior Ministry issued a statement Sunday night stressing that it will "maintain order rigorously" in the region. The government has accused leftist groups - particularly ETA, the Marxist-Leninist liberation movement - of orchestrating the amnesty demonstrations in an attempt to subvert the June 15 paliamentary elections.

But Basque moderates, including Pamplona and San Sebasitan city councilmen, have blamed unrest on the government's belief that regional political problems and aspirations can be solved with promises and the use of force.

Observers have interpreted the government's hardened stand as a sign that Premier Suarez has written off Basque support in next month's election.

Basque voters stayed away in droves from the December referendum for constitutional reform saying they were not incuded in the Street program.