Enraged protesters have stormed Paraguay’s congress leaving it in flames after the Senate secretly voted on a constitutional amendment to allow President Horacio Cartes to run for re-election.

The proposal was to go to the House, where it appeared to have strong support. The chamber’s President Hugo Velazquez said that a vote, expected to take place early on Saturday, was called off until the situation calmed down. “I call for calm,” Velazquez said. “Tomorrow we will not take any decision; we will not hold a session.”

Several Latin American countries, including Paraguay, Peru and Chile, prevent presidents from running for consecutive terms in a region where the memories of military dictatorships remain all too vivid.

Senator Desiree Masi from the opposition Progressive Democratic Party reportedly called the vote a ‘coup’ and invited citizens to join her in resisting it.

Violent confrontations ensued. They escalated for hours as riot police responded with tear gas and rubber bullets. Several people were inside the congress building as the fire took hold and a number of politicians, police and journalists were injured. The exact number of casualties is still unknown.

Senator Carlos Filizzola scrambled to defend the Secret ballot saying:

“Nothing was done outside of the framework of the constitution. I repeat, the session that we had today with the 25 senators was all done within the law, complying with regulations.”

The secret session – held in a locked office in congress rather than on the senate floor – included 25 Senators out of 45. That is just enough votes for it to pass to the House.

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