The death toll in the suicide attack targeting one of Pakistan’s oldest and most revered Sufi shrines in Lahore has risen to 13 as another civilian succumbed to his injuries, a media report said on Monday.

Tahir Aslam, 18, was working at a shop near the shrine. He was among the critically injured and was brought to the Mayo Hospital where he has succumbed to his injuries.A senior police official told the daily on condition of anonymity that security forces had yet to make any substantial progress in the investigations into the attack. He said that although they had arrested a few suspects from Lahore, they were no big leads.

A suicide bomber blew himself up outside the Data Darbar shrine, the largest Sufi shrine in South Asia on Wednesday, the second day of the the fasting month of Ramzan.Punjab Inspector General of Police Arif Nawaz has said it was a suicide attack as the target was the vehicle of the elite force that was stationed outside the shrine of Sufi saint Ali Hajvari commonly known as Data Darbar.

“Police was the target. 100 per cent,” he said.Lahore police spokesman Syed Mubashir has said the police have arrested four suspects with the help of CCTV cameras in the city.The rickshaw used to transport the suicide bomber to the shrine has been identified, he added.Prime Minister Imran Khan condemned the attack and has directed the Punjab government to provide all assistance to the injured and families of victims.

Punjab Chief Minister Usman Buzdar has ordered an inquiry into the attack.The famous shrine is visited by hundreds of thousands of people each year. In 2010, the heavily-guarded shrine was targeted in a suicide attack that killed more than 40 people.Police also confirmed that Hizbul Ahrar had claimed responsibility for sending the teenage suicide bomber to the shrine.