MEXICO CITY—The U.S. Geological Survey says an earthquake with a preliminary magnitude of 5.9 struck the southern Mexican state of Oaxaca Monday morning, frightening residents already shaken by a powerful quake two days earlier.

There were no immediate reports of casualties or damage days after a more powerful temblor hit the same area.

The epicentre of the quake, which struck just before 0700 GMT Monday, was about 30 kilometres northeast of the town of Santa Catarina Mechoacan. It had a depth of 40 metres.

People fled their buildings after an earthquake alarm sounded in the early morning hours, gathering in the streets in their pyjamas. It was the second time in days that the earthquake alarm sounded in the capital, giving residents a short window to exit buildings before they began to sway.

On Friday, Mexico escaped major destruction from a magnitude 7.2 earthquake that jolted southern and central parts of the country, though 13 people were killed in the crash of a helicopter sent to assess the damage. The epicentre of that quake wasn’t far from the latest one.

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