The quake struck 93 km (58 miles) northwest of San Luis, which lies in the shadow of the Andes mountains, at a depth of 184 kilometres, USGS data showed.

Local journalist Alejandro Costanzo said that while the tremors did not feel strong in the city, they lasted a long time. He said he had seen no immediate signs of damage in San Luis.

"Buildings here are designed for this kind of event," Costanzo told television station TN from San Luis, adding that the surrounding region was lightly populated.