ASUNCION (Reuters) - Two top Paraguayan government officials were fired on Saturday after a protester died in violent clashes sparked by a secret Senate vote on a constitutional amendment that would allow President Horacio Cartes to run for re-election.

While the capital city Asuncion had calmed down the day after Paraguay’s Congress was stormed and set on fire, protests may resume if the lower house votes on the amendment next week.

The violent upheaval punctured a period of relative stability under Cartes, in which the soy and beef exporting nation became one of South America’s fastest-growing economies and began to move past a long history of political uncertainty.

Rodrigo Quintana, 25, was killed by a rubber bullet fired by police who entered the headquarters of the Liberal Party, the country’s second-largest, opposition politicians and a federal prosecutor said.

Four officers were fired in addition to Interior Minister Tadeo Rojas and the national police chief, Crispulo Sotelo. An investigation into the death is underway.

In a Facebook message on Saturday, Cartes said the loss of Quintana’s life was “unjustifiable” and “a calamity.” He pledged to hold those responsible accountable and said he would submit to “self criticism.”

The country’s constitution has prohibited re-election since it was passed in 1992 after a brutal dictatorship fell in 1989. Sensitivities to holding on to power and perceived police aggression persist.

“It was an exaggerated reaction but this is what President Cartes and his friends who provoked the re-election amendment wanted,” said Pablo Noguera, a 25-year-old student “This goes against the Constitution and now they want to do everything in the dark.”

Paraguay’s Senate voted on Friday during a special session in a closed office rather than on the Senate floor. Twenty-five lawmakers voted for the measure, two more than the 23 required for passage in the 45-member upper chamber.

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Opponents of the measure, who claim it would weaken Paraguay’s democratic institutions, said the vote was illegal.

The re-election measure would apply to future presidents and Cartes, a soft-drink and tobacco mogul elected to a five-year term in 2013.

BLOOD SPILLED

The proposal will require approval by the House, where it appeared to have strong support. A vote which had been expected early on Saturday was called off until the situation calmed down, said the chamber’s president, Hugo Velazquez.

A popular referendum would also be required to change the law prohibiting re-election.

Meetings for the Inter-American Development Bank’s (IADB) annual board of governors went ahead as scheduled on Saturday.

IADB President Luis Alberto Moreno called for peace and dialogue and said Paraguay would continue to be a vital partner of the regional bank.

Political instability in the country of 6.8 million is a concern for its much larger neighbors Brazil and Argentina, which have increasingly looked to Paraguay for business and manufacturing opportunities.

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The region is already worried about unrest in Venezuela, where President Nicolas Maduro on Saturday moved to quell protests and international condemnation. The pro-government Supreme Court revoked its controversial annulment of the opposition-led Congress.

One member of Paraguay’s lower house of Congress, who had been participating in protests on Friday, underwent surgery after also being hit by rubber bullets. Several politicians and journalists were injured, local media reported, and the government said several police were hurt.

Charred debris and glass from broken windows littered the steps of Congress.

Around 200 protesters were detained, police said, and Amnesty International published a statement demanding their release. Opposition politicians said they would not forget the violence.

“We have a commitment to the blood Rodrigo spilled ... we will continue the fight,” Liberal Party Senator Miguel Saguier said at a press conference.