UPDATE 1-Mexico City mayor contracts coronavirus, says she has no symptoms

(Adds details on mayor, coronavirus in Mexico)

MEXICO CITY, Oct 27 (Reuters) - Mexico City Mayor Claudia Sheinbaum, a close ally of President Andres Manuel Lopez Obrador, said on Tuesday she had tested positive for the novel coronavirus but was feeling well and had not developed symptoms of the COVID-19 disease.

Writing on Twitter, Sheinbaum said she had been informed on Monday night of her positive test and would continue to work and coordinate all activities from a safe distance.

Unlike Lopez Obrador, Sheinbaum has appeared regularly in public wearing a face mask. She has been at pains to demonstrate the city government is taking the pandemic seriously.

The 58-year-old scientist is viewed by political analysts as one of the top contenders to succeed Lopez Obrador in 2024.

Sheinbaum's announcement followed warnings by the government that infections were picking up in parts of the country. Late last week, the large northern border state of Chihuahua returned to the highest phase of coronavirus alert.

On Saturday, a senator from the ruling National Regeneration Movement (MORENA) died after contracting COVID-19.

Earlier on Tuesday, Lopez Obrador declared three days of national mourning for victims of the disease to coincide with Day of the Dead celebrations this weekend. (Reporting by Diego Ore; Editing by Dave Graham and Grant McCool)