COSTA RICA'S PROTESTING FLAMINGS

THOUSANDS marching in the streets. Flaming barricades. Clashes between demonstrators and riot police in darkened streets. A semi-truck hollowed out by fire.

Costa Rica has been rocked all last week by the kind of protests rarely seen in this country in comparison with its more tumultuous Central American neighbours.

It comes during a labor strike that went into its fifth day Friday with absolutely no apparent end in sight.

Spurred by calls from public sector unions, demonstrators protested again outside the  presidential residence and blockaded roads in different parts of the country to demand Preident Carlos Alvarado scrap a proposed fiscal reform before congress that includes new taxes.

Costa Rica's government is struggling with a deficit estimated at  7.1 percent of GDP this year, which has pushed up the public debt load and increased its need for revenue.

Alvarado is proposing to implement a  value added  tax to replace the existing sales tax and expand it to  goods and services  that are currently exempt.

One of the most controversial measures is a 1 percent duty on basic foodstuffs.

Those and other changes that would limit  unemployment  assistance and the payment of some salary bonuses have met with vigorous opposition from public-sector  unions.

Social Security officials reported a daily staff absentee rate of 13 percent  to 26 percent, causing dozens of surgeries to be postponed.

''Here are people demanding no more taxes on the working class, no more burdens on workers,''  said Melida Cedeno, president of the APSE teacher union.

''This strike is indefinite,'' she added, ''and will end only when the government has the will to sit down at the table to talk with all the workers.............and withdraw the proposed law."

Alvarado, in a televised address called the strike,  ''illegal'' , promised to guarantee public order and said the reforms are   ''the only way to avoid an imminent crisis.............Today their approval is not only necessary but also urgent. [Agencies]