At least one person died and two others were injured after a bomb exploded in Mexico City's central tourist area, the city's Public Security Chief Joel Ortega said.
"It sounded like back-to-back explosions... One person is dead, a man, and we have a woman in critical condition with burns all over her body," Ortega said on Friday.
No group has come forward claiming responsibility for the blasts, which shattered windows and billboards in the vicinity. The explosions occurred at 2:30 pm (2030 GMT) near the tourist area known as the Zona Rosa (Pink Zone), where dozens of ambulances, patrol cars and two helicopters have converged.
"It was a home-made explosive device probably activated by cell-phone and probably made with gunpowder, judging from the smell," said Ortega.
He said police were investigating whether the deceased was the trigger man in the attack or simply a passerby who picked up a red bag where the device was stashed.
"We noticed the dead man lost a hand and this surely happened the instant he handled the device," the official said.
A young man also sustained a hand injury in the blast, a police spokesman said.
"We received no warning call" about the bombing, Ortega added.
In July and September the leftist Popular Revolutionary Army rebel group set off bombs damaging a gas pipeline owned by the state-run PEMEX oil company.
Apart from rebel groups, Mexican media also speculated that yesterday's attacks could be attributed to the country's powerful drug trafficking cartels.