At least 20 people have been killed and 40 wounded after a bomb exploded at a vegetable market in northwest Pakistan. The blast happened in the city of Parachinar, a mainly Shia Muslim area on the Afghan border. The market was full of shoppers when the device exploded. Officials said the death toll was expected to rise. A faction of the Pakistani Taliban (TTP) said it was behind the blast, adding its goal was “to avenge the killing of our associates”. The group’s spokesman said it wanted to “teach a lesson to Shiites for their support for Bashar al-Assad,” referring to the Syrian president. The spokesman warned that his Sunni Muslim group will continue attacking Shia Muslims if they back President Assad, whose regime is entrenched in a six-year civil war that has claimed more than 310,000 lives.