QUETTA: A 5.1-magnitude earthquake struck southwestern Pakistan on Friday, but officials said there were no immediate reports of damage or casualties.

The epicentre was close to the city of Sibi, in Balochistan province, at a depth of 71 kilometres, a meteorological official, Mahwish Ahmad told AFP.

The quake, measured by the US Geological Survey at a 4.9 magnitude, comes a week after one person was killed and 30 injured in a series of small tremors in southern Pakistan.

Pakistan straddles part of the boundary where the Indian and Eurasian tectonic plates meet, making the country susceptible to quakes.

The country was hit by a 7.6-magnitude earthquake on October 8, 2005 that killed more than 73,000 people and left about 3.5 million homeless.

A 7.7-magnitude earthquake devastated several areas in southwestern Balochistan province, in September last year.

It killed at least 376 people and left some 100,000 others homeless.