Pakistani officials on Tuesday said two police officers and four paramilitary troops have been killed, plus over a hundred more security forces injured, after a standoff with supporters of jailed former prime minister Imran Khan turned violent in the capital of Islamabad.

The government has deployed military forces with shoot-on-sight orders to restore order.

Islamabad went on lockdown over the weekend as a column of Khan supporters marched on the city, egged on by the imprisoned former PM and his wife Bushra Bibi. Their plan was to occupy the central government square and demand the immediate release of Imran Khan, who was jailed on several of the hundreds of corruption and abuse of power charges leveled against him.

Members of Khan’s Pakistan Tehreek-i-Insaf (PTI) party also want the current government to resign, accusing it of gaining power only by rigging the February elections. PTI was actually the biggest winner in those elections, even though it was banned from the ballot and forced to run its candidates as “independents.”

The government ordered Khan’s army to stay out of the government district, vowing to arrest anyone who bypassed a hastily-constructed barricade of shipping containers. Protesters broke through the ring of shipping containers on Tuesday and battled security forces, resulting in hundreds of injuries and six reported deaths.

The Pakistani army, which is not fond of either Imran Khan or his PTI faithful, moved in and took control of Islamabad’s D-Chowk square on Tuesday, reinforced by police and troops from the Pakistan Rangers, a paramilitary federal law enforcement unit.

Radio Pakistan reported on Monday night that a vehicle rammed into a group of Pakistani Rangers on a highway leading into Islamabad on Monday night, killing four of them and severely wounding five others. Protesters attacked other Rangers personnel with improvised weapons on the outskirts of the city. Two police officers were reportedly killed during clashes with the protesters.

The military said drastic measures were justified because D-Chowk square houses important government buildings, and because visiting Belarusian dictator Alexander Lukashenko is currently in residence there.

Interior Minister Mohsin Naqvi said the troops protecting D-Chowk square will use deadly force if the protesters challenge them. He said a strict curfew might be imposed in Islamabad if violence continues.

“We have now allowed police to take any decision according to the situation,” Naqvi warned.

Naqvi said the protesters have inflicted serious injuries on security personnel with “stone-pelting” tactics. According to Radio Pakistan, the military has been instructed to “deal with the miscreants with an iron hand,” including orders to “shoot miscreants and troublemakers on sight.”

Prime Minister Shehbaz Sharif condemned “attacks on police and Rangers under the guise of a so-called peaceful protest.”

“Pakistan cannot afford any form of chaos or bloodshed. Bloodshed for nefarious political agenda is unacceptable and highly condemnable,” he said.

The protesters have also attacked journalists, including an Associated Press (AP) videographer who suffered serious head injuries when the mob assaulted him and stole his camera. PTI officials urged their supporters not to attack reporters, and claimed those “deplorable” assaults might have been carried out by “troublemakers” mixed into the protest march.

The protesters ignored both government threats and an offer to give them space for demonstrations on the outskirts of Islamabad, pushing all the way up to the military cordon deployed around D-Chowk Square. As night fell, Bushra Bibi was reportedly approaching the square in a slow-moving, heavily-guarded convoy of demonstrators.

“Our plan will not change until Imran Khan comes out and tells us what to do,” Bibi told the crowd.

Bibi and her supporters appeared to back off after dark, pulling back from D-Chowk Square and camping around the city. Several of them told reporters they would not leave Islamabad until Khan was freed.

Interior Minister Naqvi claimed Imran Khan himself agreed to hold demonstrations outside the city, but he was overruled by other PTI officials, who were permitted to meet with Khan in prison twice on Monday as the crisis escalated.

“Maybe there is a leadership above Imran Khan who has refused to accept this,” Naqvi mused.