Explosion outside the Data Darbar shrine kills at least 10 people and wounds many more, officials say.

Islamabad, Pakistan – At least ten people have been killed and more than 20 wounded in a blast outside a prominent Sufi shrine in the eastern Pakistani city of Lahore, rescue and police officials said.

The explosion took place on Wednesday morning targeting a police security vehicle outside the Data Darbar shrine in Pakistan’s second largest city.

At least five policemen were among the dead, provincial police chief Arif Nawaz told reporters shortly after the attack.

“We are still investigating whether it was an IED [improvised explosive device] or a suicide attack,” said Ashfaq Ahmed, a senior police official.

Footage from the scene showed a badly damaged police vehicle and debris strewn in front of the shrine.

“They were elite [police] officers standing there for security at Gate Two of the Data Darbar [shrine],” Ahmed told reporters.

Rescue services spokesman Muhammad Farooq told Al Jazeera that at least five of those wounded were in critical condition and being treated at Lahore’s Mayo Hospital.

“The rescue operation at the site of the blast has been completed. Investigating agencies are now at the scene and are doing their work,” he said.

Nawaz, the provincial police chief, said police were the target of the bombing.

“Police were the target because the direction [the attacker] came from, he could have done a lot of damage [in the market], but he went straight to the vehicle,” he said.

General threats

Data Darbar is one of the country’s most well-known and venerated shrines, with thousands thronging to the final resting place of Sufi saint Abul Hassan Ali Hajveri every day.

The numbers have gone up since the beginning of the Muslim holy month of Ramadan on Tuesday in Pakistan.

Police official Ahmed said there had been general threats of attacks, but no specific threat against the shrine.

“I will say this to all Pakistanis: because we enter mosques to pray and offer Taraweeh [special Ramadan prayers], please keep an eye on your surroundings at all times,” said Mian Aslam Iqbal, the provincial health minister.

No group immediately claimed responsibility for the attack.

The country has been battling the Pakistan Taliban – known by the acronym TTP, an armed group that demands the imposition of a strict interpretation of Islamic law – and its allies since 2007.

A series of security operations since 2014 has displaced the group from its base in Pakistan’s northwestern tribal areas and in neighbouring Afghanistan.

Violence has dropped dramatically from its peak in the late 2000s, but sporadic high-casualty attacks continue to target civilians and security forces.

In recent years, the Islamic State of Iraq and the Levant (ISIL or ISIS) armed group has also claimed responsibility for a number of attacks targeting shrines and members of minority Muslim sects.

In 2010, Data Darbar was struck in what was then one of the deadliest suicide attacks on a Sufi shrine in Pakistan, killing at least 42 people and wounded scores more.

Asad Hashim is Al Jazeera’s digital correspondent in Pakistan. He tweets @AsadHashim