The mayor of the Latin American city hardest hit by the coronavirus has urged regional governments to take drastic steps to slow its spread and avoid the devastation she said had left Guayaquil looking like a war zone.

Cynthia Viteri told the Guardian she believed thousands had probably lost their lives in the Ecuadorian port city in recent weeks and compared Covid-19’s deadly impact there to “an unexpected bomb falling on a peaceful town”.

“It was as if we were attacked from the air like in Hiroshima,” said Viteri, a 54-year-old lawyer and former presidential candidate who sent desperate tweets as the scale of the dystopia unfolding there became clear.

“It was the horror of a war – there were dead in the streets, dead in homes, there were dead outside the hospitals,” remembered Viteri, who was infected and placed in quarantine but has recovered.

The precise scale of Guayaquil’s tragedy remains unclear although few doubt the number of deaths far exceeds Ecuador’s official nationwide death toll of 507.

Viteri said independently gathered figures from cemeteries and graveyards suggested the death toll in Guayaquil alone could be more than 8,000.

She claimed the figures showed that in the first two weeks of April alone, more than 5,000 people had died of Covid-19 in Ecuador’s main commercial hub, which has close to 3 million inhabitants.

Mayor Cynthia Viteri works with a door-to-door health outreach programme amid the outbreak. Photograph: Santiago Arcos/Reuters

Last week, official data suggested the number of deaths in Guayas province – of which Guayaquil is the capital – leapt from a normal average of 3,000 to nearly 11,000 in the six weeks between the beginning of March and mid-April.

Viteri said she hoped the political leaders of other Latin American countries and cities could learn from Guayaquil’s calamity.

Last week, Brazil’s former president Luiz Inácio Lula da Silva told the Guardian he feared some parts of his country could witness similar scenes to the “horrific, monstrous images we saw in Guayaquil” in the coming weeks and months.

Lula accused Brazil’s current leader, Jair Bolsonaro, of leading Brazilians “to the slaughterhouse” by deliberately undermining social distancing measures and efforts to lock down major cities such as Rio de Janeiro and São Paulo, which have been partially paralysed by their governors.

Viteri said such shutdowns were essential.

“If we have learned a lesson that Guayaquil can leave for the world, and it’s a painful lesson, it is: ‘Don’t run from the disease; pursue it, knock on doors and save people before [the virus] gets in their lungs,’” she said.

Viteri said any country that had so far failed to lock down should “look in our mirror and apply preventive measures straight away”.

Three weeks after the collapse of Guayaquil’s health and mortuary services shocked the world, Viteri claimed authorities were regaining control and said officials had “resisted [the virus] like Spartans”.

Soldiers and police have cordoned off often poorer virus-hit neighbourhoods, enforcing strict lockdowns, and a municipal taskforce made up of medics, firefighters and city workers has gone house to house looking for potential cases while sanitary workers have disinfected and fumigated public areas.

Authorities have also created a corpse-collecting taskforce and distributed cardboard coffins to bereaved families.

People line up outside of a pharmacy in Guayaquil. Photograph: Santiago Arcos/Reuters

Viteri said Guayaquil was building two cemeteries for victims in addition to two others being built by the central government but she admitted hospitals continued to be overwhelmed by the number of coronavirus patients.

Experts say one possible reason for the number of cases in Guayaquil is the high level of air traffic between Ecuador and Spain, which has the world’s third-highest number of deaths, after the United States and Italy.

Spain, where more than 21,000 people have died, is home to more than 400,000 Ecuadorian migrants and the first Covid-19 case recorded in Ecuador was of a 71-year-old woman who flew into Guayaquil from Madrid in mid-February. She died there on 13 March.

A failure to properly enforce social distancing in the weeks after coronavirus arrived is also suspected to have played a role.