One Pakistan Tehreek-e-Insaf (PTI) worker was killed and six others were injured on Tuesday in a firing incident at a protest rally in Quetta, The Express Tribune reported.

Supporters of former Pakistan Prime Minister Imran Khan blocked the main Quetta Airport Road to protest against his arrest. A firing incident took place in the PTI rally, The Express Tribune reported citing a senior police officer who requested anonymity as he was not authorized to speak to the media.

PTI Balochistan President Munir Baloch accused the police of firing on the protesters. Baloch demanded an investigation into the incident. Imran Khan was arrested by Rangers personnel from Islamabad High Court (IHC) on Tuesday.

Angry protesters burnt two police vehicles parked near the rally and pelted stones as police used tear gas to disperse the supporters of former Pakistan PM Imran Khan, as per The Express Tribune report.

Protesters burnt tyres on the main Airport Road Chowk, suspending traffic movement between Quetta and other parts of Balochistan. The protesters blocked the main national highways in Balochistan which linked Pakistan with Iran and Afghanistan.

According to a Balochistan police spokesperson, three police officers were injured when protesters fired on them, as per the news report. In order to maintain peace, the Balochistan government has announced Section 144. Balochistan Home Minister Ziaullah Langove said that the government has imposed a ban on all kinds of political rallies and the display of weapons.

PTI workers protested in cities across the country, including Islamabad, Rawalpindi, Lahore, Karachi, Gujranwala, Faisalabad, Multan, Peshawar, and Mardan, reported Geo News. In Karachi, protesters clashed with the police near Nursery.

They pelted stones at police vehicles and tore down street lights. There were reports that police fired teargas shells at the demonstrators. Police also fired teargas shells at protesters on Rawalpindi's Murree Road.

PTI supporters chanted "Release Imran Khan," and "Shut down Pakistan," in the streets of Lahore, Faizabad, Bannu, and Peshawar. "People of Lahore moving from Liberty towards Lahore Cantt," tweeted PTI's handle.

Imran Khan was arrested by Rangers personnel from Islamabad High Court (IHC) -- acting on National Accountability Bureau's (NAB) warrant. The PTI chairman was arrested as part of NAB's investigation in the Al-Qadir Trust case ahead of his appearance before the IHC to seek bail in multiple FIRs registered against him.

Rangers personnel driving a black Toyota Hilux Vigo took Imran Khan away to NAB Rawalpindi, reported Geo News. Khan, along with his wife Bushra Bibi and other PTI leaders, is facing a NAB inquiry related to a settlement between the PTI government and a property tycoon, which reportedly caused a loss of 190 million pounds to the national exchequer.

As per the charges, Khan and other accused allegedly adjusted Rs50 billion -- 190 million pounds at the time -- sent by Britain's National Crime Agency (NCA) to the government. They are also accused of getting undue benefit in the form of over 458 kanals of land at Mouza Bakrala, Sohawa, to establish Al Qadir University.