The interim president of Peru, Manuel Merino, has stepped down amid nationwide fury over the killing of two protesters in a brutally heavy-handed police clampdown on huge pro-democracy demonstrations on Saturday. In a televised address to the nation, Merino announced his resignation and insisted he acted within the law when he was sworn into office as chief of state on Tuesday, following congress’s removal of the elected president in an impeachment vote. News of the resignation was followed immediately by the sound of honking car horns, pot banging and cheers in neighbourhoods across the Peruvian capital. The death of two men in their 20s from gunshot wounds on Saturday boosted the public clamour for Merino’s resignation. The victims – identified as Jack Brian Pintado Sánchez, 22, and Jordan Inti Sotelo Camargo, 24 – were the first deaths in nearly a week of unrest over the controversial removal of Martín Vizcarra as president and his replacement by a de facto government, regarded by many Peruvians as a coup. “They say he was injured with a bullet in the heart, he died like that and was brought in as corpse,” Sotelo Camargo’s father told local journalists at the entrance of the Lima hospital where his son’s body had been taken, calling on Merino to take responsibility. Peru’s human rights coordinator reported that more than 40 people were missing following Saturday’s march amid multiple reports of heavy-handed police repression against largely peaceful demonstrators. The health ministry reported that more than 90 people were being treated for injuries. Images from the protests on Saturday showed hundreds of riot police using batons and shields against largely peaceful protesters, teargas and buckshot being fired directly at crowds or individuals and tanks using water cannon. There were even reports of teargas being fired from helicopters flying overhead in downtown Lima, from where protesters reported street lights being switched off and mobile phones blocked during the march. Daily protests mounted during the week, culminating in nationwide demonstrations demanding the resignation of Merino, the former speaker of congress, with tens of thousands of people filling the streets of Lima and dozens of towns and cities. “There was irrational, abusive use of force in Lima. I demand that the president of the republic shows his face and gives explanations to the country,” said Peru’s human rights ombudsman, Walter Gutiérrez. Erika Guevara, Americas director for Amnesty International, said: “We demand impartial investigations into the human rights violations in the protests in Peru including the deaths of two young students. Who committed these crimes and their senior officials must be investigated at the highest level.” “Two young people have been sacrificed absurdly, stupidly, unjustly by the police,” Mario Vargas Llosa, the Peruvian author and Nobel laureate, said in a video message. I believe it is imperative that the repression – which is against all Peru – ceases, because it is all Peru which is protesting.” The abrupt replacement of the popular president by Merino, a little-known politician with a questionable track record, caused uproar across the Peruvian capital, sparking some of the largest demonstrations in more than a decade. George Forsyth, the politician leading the polls as a presidential candidate for the elections next year, had demanded Merino’s immediate resignation, saying in a tweet that his “hands were stained with blood”. He said congress should choose a new president from the 19 lawmakers who voted against Vizcarra’s impeachment over unproven bribery allegations. Out of 130 members of congress, 105 voted to remove the centrist leader on Monday. The former president expressed his sadness over the deaths. “I deeply regret the deaths caused by the repression of this illegal and illegitimate government,” Vizcarra wrote. “My condolences to the families of these civil heroes who, exercising their right, went out in defence of democracy and in search of a better country. The country will not allow the death of these brave young people to go unpunished.”