Bolivia’s political crisis turned deadly after security forces opened fire on supporters of Evo Morales in a central town, killing at least five people, injuring dozens and threatening the interim government’s efforts to restore stability following the resignation of the former president in an election dispute.

Most of the dead and injured Friday in Sacaba near the city of Cochabamba suffered bullet wounds, Guadalberto Lara, director of the town’s Mexico Hospital, told The Associated Press. He called it the worst violence he’s seen in his 30-year career.

Angry demonstrators and relatives of the victims gathered at the site of the shootings, chanting: "Civil war, now!"

Morales, who was granted asylum in Mexico after his resignation Sunday, said on Twitter that a "massacre" had occurred and he described Bolivia’s government led by interim President Jeanine Áñez as a dictatorship.

"Now they are killing our brothers in Sacaba, Cochabamba," he said in another tweet.

Protesters said police fired when demonstrators, including many coca leaf growers who backed Bolivia’s first indigenous president, tried to cross a military checkpoint. Emeterio Colque Sánchez, a 23-year-old university student, said he saw the dead bodies of several protesters and about two-dozen people rushed to hospitals, many covered in blood.

Earlier in the day, Áñez said Morales would face possible legal charges for election fraud if he returns home from Mexico City, even as the ousted leader contended he is still president since the country’s legislature has not yet approved his resignation. Bolivia’s interim leader also said Morales would not be allowed to participate in new presidential elections meant to heal the Andean nation’s political standoff.

Morales stepped down on Sunday following nationwide protests over suspected vote-rigging in an Oct. 20 election in which he claimed to have won a fourth term in office. An Organization of American States audit of the vote found widespread irregularities. Morales has denied there was fraud.

Families of the victims held a candlelight vigil late Friday in Sacaba. A tearful woman put her hand on a wooden casket surrounded by flowers and asked: "Is this what you call democracy? Killing us like nothing?" Another woman cried and prayed in Quechua over the coffin of Omar Calle, which was draped in the Bolivian national flag and the multicolor "Wiphala" flag that represents indigenous peoples.

Bolivia’s Ombudsman’s Office said it regretted the deaths during the joint police-military operation and called on the interim government to investigate if the security forces had acted within the constitution and international protocols on human rights.

"We express our alarm and concern over the result of an attempt to stop a demonstration by coca leaf growers from entering the city of Cochabamba," it said.

Presidency Minister Jerjes Justiniano told reporters in La Paz that five people had been killed and an estimated 22 were injured. Lara, the hospital director, said that 75 people were injured.

Justiniano called for a dialogue with all parties involved in the conflict.

"What we’ve been able to determine through preliminary information is that they used military weapons," he said.

On Thursday, Morales told The AP in Mexico that while he had submitted his resignation, it was never accepted by Congress.

"I can say that I’m still president," he said.

Morales said he left because of military pressure — the army chief had "suggested" he leave — and threats of violence against his close collaborators.

Áñez dismissed the explanation.

"Evo Morales went on his own; nobody kicked him out," she said at a news conference.

"He knows he has accounts pending with justice. He can return but he has to answer to justice for electoral fraud," she added.

Supporters of Morales, who had been Bolivia’s president for almost 14 years and was the last survivor from the "pink tide" of leftist leaders who come to power in South America, have been staging disruptive protests since his ouster, setting up blockades that forced closure of schools and caused shortages of gasoline in the capital.

In the capital, riot police fired tear gas at rock-throwing demonstrators. Elderly people and children were caught in the violence and tried to seek shelter in businesses that had been shut behind metal sheets to protect against looters. Long lines formed outside some gas stations in La Paz after blockades in the nearby city of El Alto, a major distribution point for fuel.

"There’s no gas," said Efraín Mendoza, a taxi driver from El Alto, who was forced to buy gasoline on the black market at twice the regular price.

"Products are scarce. There’s no meat, no chicken, people are making long lines. It’s all because of the blockades," he said. "There’s division in Bolivia. It’s exasperating."

Áñez, the highest-ranking opposition official in the Senate, proclaimed herself president, saying every person in the line of succession ahead of her —all of them Morales backers — had resigned. The Constitutional Court issued a statement backing her claim that she didn’t need to be confirmed by Congress, a body controlled by Morales’ Movement Toward Socialism party.

Much of the opposition to Morales sprang from his refusal to accept a referendum that would have forbidden him from running for a new term.

Morales had upended politics in this nation long ruled by light-skinned descendants of Europeans by reversing deep-rooted inequality. The economy benefited from a boom in prices of commodities and he ushered through a new constitution that created a new Congress with seats reserved for Bolivia's smaller indigenous groups while also allowing self-rule for all indigenous communities.

But many people became disenchanted by his insistence on holding on to power.