Nine people were injured by an explosion in the main square of Mexico’s Pacific coast resort of Acapulco, officials said Monday.

Prosecutors in the southern state of Guerrero did not specify what caused the explosion late Sunday, but some of the injured had burns, suggesting a flammable device. One of the victims, a baby, was in serious condition.

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Officials did not specify whether the victims were local residents or tourists, but the restaurant-lined square is popular among both. The state government statement said it was "taking care of Acapulco residents as well as tourists, following the incident."

Acapulco, which was hit by Category 5 Hurricane Otis in October, has long seen grisly violence.

In late May, the bodies of four men and two women were found strangled and dumped in a pile in Acapulco. The bodies were found on a street with their hands tied behind their backs. The previous week, five dismembered bodies found scattered on a street in Acapulco. One of the victims was a candidate for a town council seat in the nearby town of Coyuca de Benítez.

But the violence in Acapulco usually involves targeted attacks or small groups of bodies turning up in the streets. Mass indiscriminate attacks on passersby in town squares are still relatively rare in Mexico.

Acapulco is still struggling to recover after being hit by Category 5 Hurricane Otis in October. Otis left at least 52 dead and destroyed or damaged most hotels.