Workers of the recently proscribed Tehreek-i-Labbaik Pakistan (TLP) "brutally tortured" a deputy superintendent of police (DSP) and took him, as well as four other officials, hostage on Sunday, spokesperson for Lahore CCPO Rana Arif told Dawn News.

The clash started when the police launched an operation to clear the area around Lahore's Yateem Khana Chowk, where workers of the banned party have been staging a protest since earlier this week.

"Workers attacked police with petrol bombs," the spokesperson told Dawn News.

Arif said 11 police officials were injured after "brutal torture" by TLP workers and were under treatment at different hospitals in the city.

Meanwhile, at least three protesters were killed and several others injured during the clash, according to the party's workers, reports the Pakistani newspaper.

In a video message, a spokesperson for the banned party, Shafiq Ameeni, alleged that "forces suddenly attacked [us] at Lahore Markaz at 8am today morning in which a large number of our workers have been martyred while many are injured".

"[We] will bury [those killed] when the French ambassador exits the country and our agreement (with the government) is implemented," he was quoted as saying by Dawn News.

According to reports, Lal Masjid Islamabad  cleric Mufti Abdul Aziz has extended his support to the TLP.

The Pakistan media has been instructed not to report clashes, sources said.

Meanwhile, PM Imran Khan tweeted: "Let me make clear to people here & abroad: Our govt only took action against TLP under our anti-terrorist law when they challenged the writ of the state and used street violence & attacking the public & law enforcers. No one can be above the law and the Constitution."