At least six people have been killed and 20 others injured in a suspected suicide attack targeting census workers and their security escort in the Pakistani city of Lahore.

Four of the dead were troops.
It comes amid a series of bombings claimed by Islamist militants in recent weeks. The Pakistani Taliban said they carried out the attack.
The site of the blast near Bedian Road has been cordoned off.
It was not immediately clear if the two civilians killed were census workers or bystanders.
Security forces have been frequent targets for the militants.
The Taliban statement said the attack was carried out in revenge against security personnel.
The militants have been hitting back after military operations against them in the north-west.
In February a Taliban faction said it carried out a bomb attack in Lahore, which killed 13 people and wounded more than 80.
Days later a suicide bomb attack at a shrine in the southern town of Sehwan was claimed by the so-called Islamic State (IS). Police said 90 people were killed.