At least 11 people have been killed and 20 wounded after twin blasts in southwestern Pakistan. 

A police spokesman Shahzada Farhat said the first explosion which was near the police chief’s office in Quetta was powerful enough that it was heard across the city, shattering windows on nearby buildings.

Local official Nasrullah Khan said the first blast came during rush hour in a market in Parachinar, the capital of the Kurram tribal district. 

A second official said that as people rushed to rescue those wounded by the first explosion, a second blast took place.

Nasrullah Khan said: "We fear that the death toll will increase," before adding that no further details are available at this time.

The bombing comes ahead of the Muslim holiday of Eid-al-Fitr, which follows the holy month of Ramadan, expected to end this weekend.

The twin blasts followed a bombing earlier in the day outside the office of the police chief in southwestern Quetta, capital of the insurgency-wracked Balochistan province, that killed at least 13 people.

That attack was claimed by both the Islamic State and an offshoot of the Pakistani Taliban.