Peru’s interim president has announced his resignation as the country plunged into its worst constitutional crisis in two decades following massive protests unleashed when Congress ousted the nation’s popular leader.

In a short televised address, Manuel Merino said he had acted within the law when he was sworn into office as chief of state on Tuesday, despite protesters’ allegations that Congress had staged a parliamentary coup.

“I, like everyone, want what’s best for our country,” he said.

The decision came after a night of unrest in which dozens of protesters were injured from blunt force, tear gas or projectiles that rights groups say came predominantly from police using excessive force to quell the protests.

A network of human rights groups reported that 112 people had been hurt and the whereabouts of 41 others were unknown.

Health authorities said the dead included Jack Pintado, 22, who was shot 11 times, including in the head, and Jordan Sotelo, 24, who was hit four times in the thorax near his heart.

“Two young people were absurdly, stupidly, unjustly sacrificed by the police,” Peruvian writer and Nobel laureate Mario Vargas Llosa said in a recorded video shared on Twitter.

“This repression – which is against all of Peru – needs to stop.”

A swell of political leaders had urged Mr Merino to leave, with at least 13 of his 19 ministers bailing out of his newly-formed government.

The president of Congress called on Mr Merino to resign immediately and said lawmakers would vote to oust him if he refused.

“We should put above all else the lives of the Peruvian people,” said Luis Valdez, the current head of Congress, who himself plans to resign.

Mr Merino, a little-known politician and rice farmer, became Peru’s leader on Tuesday after a stunning vote by Congress to oust popular ex-President Martin Vizcarra.

As head of Congress, Mr Merino was next in line to the presidency when Mr Vizcarra was removed. But protesters contend the move amounted to an illegal parliamentary coup and refused to recognise him.

Congress kicked Mr Vizcarra out using a clause dating to the 19th century that allows the powerful legislature to remove a president for “permanent moral incapacity”.

Legislators accused Mr Vizcarra of poorly handling the pandemic and held up unproven accusations that he took more than 630,000 US dollars (£477,000) in bribes in exchange for two construction contracts while governor of a small province in southern Peru years ago.

Prosecutors are investigating the allegations but Mr Vizcarra has not been charged. A judge barred him from leaving the country for 18 months on Friday.

In remarks before Saturday’s upheaval, Mr Merino denied the protests were against him, telling a local radio station that young people were demonstrating against unemployment and not being able to complete their studies because of the pandemic.