SAN JOSE (Reuters) - Thousands of Costa Ricans kept up a fourth day of marches and a wide public workers strike on Thursday to protest a proposed fiscal reform, dealing their center-left president his first major test since taking office in May.

Slideshow ( 6 images )

President Carlos Alvarado, 38, won a run-off election against a conservative rival in one of Central America’s most stable nations, known for its eco-tourism.

He called for dialogue with protesters this week and on Thursday met with University of Costa Rica representatives, saying he aimed to reach agreements.

“This is the best way to take on the situation. We all want the best for the country,” Alvarado said on Twitter.

The demonstrations are some of the largest in a decade.

Thousands of unionized public employees began striking on Monday to reject the tax proposal, which is under discussion in Congress, arguing that it would disproportionately affect the middle and lower classes.

The reform would convert the country’s 13 percent sales tax to a Value Added Tax, affecting more products and services.

On Thursday, strikers protested in the capital and university students marched toward the presidential residence, escorted by police officers.

The largely peaceful demonstrations in a country known for its chilled-out “pura vida” approach to life did have several moments of unrest.

On Tuesday, a San Jose supermarket was looted and the entrance to a gasoline refinery was blocked, and on Wednesday, a splinter protest group tried to enter the Legislative Assembly, clashing with police. The same evening, a communications tower in the city of Puerto Limon was set afire.