A 19-year-old woman is among three people to have died from suffocation during World Cup celebrations in Mexico City on Tuesday.

A 48-year-old woman and a 44-year-old man also died after crowds descended on the city following the country's 2-0 victory over Ecuador, the capital's health authority said on Wednesday.

More than one million people took to the streets, mainly around the Angel of Independence monument in downtown, to mark the country's first World Cup knockout win since 1986, the city government said.

City Mayor Clara Brugada expressed her "most sincere condolences" to the victims' families and pledged support in the coming days.

Health authorities said emergency services treated three unconscious people at different locations around Paseo de la Reforma before transporting them to hospital.

"After performing first aid and CPR techniques on the patients, they were transferred to a hospital for specialised medical care," the city's health authority said.

All three were confirmed to have died from suffocation and identified by their families, it added.

In a social media post after the deaths were announced, Mayor Brugada urged fans to "always celebrate with responsibility, care, and empathy".

Mexico's victory sparked wild celebrations in the Estadio Azteca and across large parts of the city, where fireworks could be seen being lit long after the final whistle.

Prior to the football match, Brugada had told fans hoping to watch the game near the Angel of Independence monument to look elsewhere due to the huge crowds already gathered there.

More than 20 million people live in Mexico City's metropolitan area - making it one of the most densely populated places on the planet.

Tuesday's win sends Mexico into the World Cup's round of 16, where they could face England if Thomas Tuchel's side beat DR Congo on Wednesday.