A major 6.9-magnitude earthquake rocked southern Peru Sunday, US experts said, but there were no immediate reports of casualties or considerable damage.

The quake hit at 2321 GMT 42 kilometers (26 miles) east-northeast of the town of Tambo at a depth of 101 kilometers, according to the US Geological Survey.

Centered 467 kilometers (290 miles) southeast of the capital Lima, the quake sent panicked people into the streets of the city of Ayacucho -- home to about 150,000. It was first reported by USGS as a 7.0-magnitude event.

In the capital, however, the quake was felt as a 4.4-magnitude occurrence -- noticed by residents of highrises but not those out and about in the sprawling city of eight million.

The Pacific Tsunami Warning Center cautioned that quakes of this size "sometimes generate local tsunamis that can be destructive along coasts located within 100 kilometers of the earthquake epicenter."

"Authorities in the region of the epicenter should be aware of this possibility and take appropriate action," it added.