A gunman attacked a Shi’ite mosque in Islamabad on Friday before detonating a suicide bomb, killing at least 31 people and wounding more than 170.

The explosion occurred after guards confronted the attacker at the gates of the Khadija Tul Kubra Imambargah mosque.

Witnesses described bloodied bodies inside the mosque and dozens more injured in the surrounding gardens.

Defence Minister Khawaja Asif said the bomber had a history of traveling to Afghanistan and accused India of sponsoring the attack, though no evidence was provided, Reuters has reported.

There was no immediate response from New Delhi, which has previously denied backing militants in Pakistan.