At least 16 people were killed and 750 arrested in Venezuela amid protests Tuesday over Nicolás Maduro’s claimed electoral victory, the New York Times reported.

Protests erupted following a contentious presidential election, resulting in at least 16 deaths and around 750 arrests, according to the New York Times. Maduro was declared the winner early Monday, securing another six-year term in a victory over former diplomat Edmundo González. However, the government has yet to release full election results and there are widespread allegations of voting irregularities, acknowledged by several countries, including the United States.

Both government supporters and opponents have taken to the streets, leading to fatal confrontations. Hundreds protested outside the United Nations office in Caracas, challenging the legitimacy of the election results, the outlet reported. Robert Castellanos, an election monitor, claimed a significant discrepancy in votes in his district, favoring González over Maduro.

“We are totally united,” Castellanos said, the outlet reported. “This has been the biggest fraud in the history of Latin America.”

Jorge Rodríguez, a prominent government official, organized pro-government marches that drew a modest crowd. “We are going to Miraflores to defend our right to life, our right to freedom, and, above all, our right to choose and to defend the result of the election,” he said, the New York Times reported.

The unrest highlights a worsening crisis. Citizens in Venezuela including Olinger Montaño López and Yeison Bracho, who died in the protests, demonstrated to challenge the official results, according to the New York Times.