Islamabad - A strong earthquake struck parts of southwestern Pakistan early Wednesday, killing at least 31 people, officials said.

The quake struck just after 4 a.m. in Baluchistan, an impoverished province bordering Afghanistan. It had a preliminary magnitude of 6.4, the United States Geological Survey reported.

The province's police chief, Asif Nawaz Khos, said at least 31 people had been killed, and a local mayor said many houses were damaged.

The quake was centered about 400 miles southwest of the capital, Islamabad.

In October 2005, a 7.6-magnitude quake devastated Kashmir and northern Pakistan, killing about 80,000 people and leaving hundreds of thousands homeless.

Baluchistan is home to a long-running separatist movement but is not considered a major battleground in the fight against Taliban insurgents that plague other border regions.