ISLAMABAD--Pakistan’s former Prime Minister Imran Khan was arrested and dragged from court Tuesday as he appeared to face charges in multiple graft cases, a dramatic escalation of political tensions that sparked violent demonstrations by his angry supporters across the country.

The arrest of Khan, who was ousted in a no-confidence vote in April 2022 but remains the leading opposition figure, represented the latest confrontation to roil Pakistan, which has seen former prime ministers arrested over the years and interventions by its powerful military.

At least one person was reported killed in clashes between protesters and the military in Quetta, the capital of Baluchistan province, with another five people wounded there, while about 15 injuries were reported amid similar violence in Karachi, Peshawar, Rawalpindi and Lahore. Police fired tear gas to disperse demonstrations.

Amid the violence, officials at Pakistan’s telecommunication authority said regulators blocked social media, including Twitter, and internet service was suspended in the capital of Islamabad and other cities. Classes at some private schools were canceled for Wednesday.

Khan was removed from the Islamabad High Court by security agents from the National Accountability Bureau, said Fawad Chaudhry, a senior official with his Pakistan Tehreek-e-Insaf party, and then shoved into an armored car and whisked away.

Chaudhry denounced the arrest of the 71-year-old former cricket star as “an abduction.” Pakistan’s independent GEO TV broadcast video of Khan being hauled away.

A scuffle broke out between Khan’s supporters and police outside the court. Some of Khan’s lawyers and supporters were injured in the melee, as were several police, Chaudhry said.

Khan was taken to the garrison city of Rawalpindi, near Islamabad, for questioning at the offices of the National Accountability Bureau, according to police and government officials. He also was to undergo a routine medical checkup, police said.

Khan had arrived at the Islamabad High Court from nearby Lahore, where he lives, to face charges in the graft cases.

He has denounced the cases against him, which include terrorism charges, as a politically motivated plot by his successor, Prime Minister Shahbaz Sharif, saying his ouster was illegal and a Western conspiracy. Khan has campaigned against Sharif and demanded early elections.

Tuesday's arrest was based on a new warrant from the National Accountability Bureau obtained last week in a separate graft case for which Khan had not been granted bail. His lawyers challenged the legality of the arrest, but the court upheld it, although it added that Khan should not have been forcibly removed from the courtroom. Khan is scheduled to appear at an anti-graft tribunal on Wednesday, officials said.

“Imran Khan has been arrested because he was being sought in a graft case,” Interior Minister Rana Sanaullah Khan told a news conference. He alleged Pakistan’s treasury had lost millions of dollars while Khan was in office due to illegal purchases of lands from a business tycoon.

The National Accountability Bureau is Pakistan’s powerful anti-corruption organization that has detained and investigated former officials, including prime ministers, politicians and retired military officers. But some view the NAB as a tool used by those in power, especially the military, to crack down on political opponents. When Khan was in power, his government arrested Sharif, then the opposition leader, through the NAB.

At a news conference, Law Minister Azam Tarar said Khan was arrested because he was not cooperating with the investigations. He also denounced the violence by Khan supporters, saying that protests must remain peaceful.

“It should have not happened,” he said, shortly after TV video emerged of burning vehicles and damaged public property in parts of the country.

Authorities said they have banned rallies in the eastern province of Punjab.

As the news of the arrest spread, about 4,000 of Khan’s supporters stormed the official residence of the top regional commander in Lahore, smashing windows and doors, damaging furniture and staging a sit-in as troops there retreated to avoid violence. The protesters also burned police vehicles and blocked key roads.

Protesters also smashed the main gate of the army’s headquarters in the garrison city of Rawalpindi, where troops exercised restraint. Hundreds of demonstrators shouted pro-Khan slogans as they moved toward the sprawling building.

In the port city of Karachi, police swung batons and fired tear gas to disperse hundreds of Khan supporters who had gathered on a key road.

Raoof Hasan, another leader from Khan’s party, told Al Jazeera English television that the arrest is “blatant interference in the judicial affairs by the powers-that-be." Hasan added that Khan "was virtually abducted from the court of law.”

Khan's arrest came hours after he issued a video message before heading to Islamabad, saying he was “mentally prepared” for arrest there.

Khan was wounded by a gunman at a rally in November, an attack that killed one of his supporters and wounded 13. He has insisted, without offering any evidence, that there is a plot to assassinate him, alleging that Pakistan's spy agency was behind the conspiracy. The gunman was immediately arrested and police later released a video of him in custody, allegedly saying he had acted alone.

In a strongly worded statement Monday, the military accused Khan of “fabricated and malicious allegations” of its involvement in the November shooting, saying they are “extremely unfortunate, deplorable and unacceptable.”

The military has directly ruled Pakistan for more than half of the 75 years since the country gained independence from British colonial rule, and wields considerable power over civilian governments.

Sharif, whose government faces spiraling economic woes and is struggling to recover from last year’s devastating floods that killed hundreds and caused $30 billion in damage, slammed Khan for assailing the military.

“Let this be abundantly clear that you, as former prime minister, currently on trial for corruption, are claiming legitimacy to overturn the legal and political system," Sharif tweeted after Khan's arrest.

In a statement, the European Union urged “restraint and cool headedness” in the country, through dialogue and the rule of law.

In Washington, U.S. Secretary of State Antony Blinken and British Foreign Secretary James Cleverly both said at a news conference they were aware of reports about Khan’s arrest but declined any substantive comment. “We just want to make sure that whatever happens in Pakistan is consistent with the rule of law, with the constitution,” Blinken said.

Cleverly said he had not been briefed in detail but added, “The U.K. has a longstanding and close relationship with Pakistan. We are Commonwealth partners. We want to see peaceful democracy in that country. We want ot see the rule of law adhered to. I’m uncomfortable to speculate further without having a detailed briefing on that.”

Khan is the seventh former prime minister to be arrested in Pakistan. Zulfikar Ali Bhutto was arrested and hanged in 1979. The current prime minister’s brother, Nawaz Sharif, who also served as prime minister, was arrested several times on corruption allegations.

In March, police stormed Khan’s Lahore residence, seeking to arrest him based on a court order in a different case. Dozens of people, including police, were injured in ensuing clashes. Khan was not arrested at the time and later obtained bail in the case.

Khan came to power in 2018 after winning parliamentary elections and had initially good relations with the military which gradually soured.