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With his supporters rioting for a third day, opposition leader Nawaz Sharif blamed Pakistan's government Friday for the political turmoil set off by a court order barring him from elected office — unrest that he warned could be exploited by Islamic extremists.

Giving his first interview since the ruling Wednesday, Sharif accused President Asif Ali Zardari of "declaring martial law on democracy," a charge echoing the complaints that forced former military ruler Pervez Musharraf to give up the presidency last year.

Sharif's interview with The Associated Press came amid a surge of political squabbling that is sure to distract the government of this nuclear-armed country from grappling with the Taliban and Al Qaeda threat spreading from the tribal areas along the frontier with Afghanistan.

Pakistan also is in the middle of a tense time with neighboring India over the deadly militant attack on Mumbai, and Sharif said Zardari's pro-Western government isn't going to be able to face any of its key tasks if it continues to wage political war on him.

"It cannot concentrate on the very big issues we are confronted with," he said. "We have issues going on in the tribal area, we have this big issue in the Swat area, and we have a very ugly situation on our eastern border after the Bombay (Mumbai) killings."

The political uproar set off by the court ruling against Sharif is lining up influential civic groups led by disgruntled lawyers with Sharif's increasingly popular Pakistan Muslim League against Zardari. It's a confrontation that will also feed worries about military intervention, a frequent result of political turmoil in Pakistan.

"I think we are heading for some sort of unfortunate situation," Sharif said at his villa near Lahore, without elaborating. "There are a lot of forces — the militants, the extremists — they are all there to take advantage."

The Supreme Court ruling upheld a ban on Sharif from contesting elections because of a past criminal conviction related to the 1999 military coup that ended his second term as prime minister and put Musharraf in power.

Sharif's brother also was disqualified from continuing as head of the provincial government in Punjab, the nation's biggest and most populous region. Zardari ousted the government there and installed a loyalist as governor.

Other critics have alleged that Zardari influenced the Supreme Court decision to neutralize Sharif and consolidate the power of his own party, which holds a majority in the national Parliament. His supporters deny he had any role in the ruling.

Former President George W. Bush's administration often referred to Sharif's party as more religious than secular. But Sharif insisted in the interview that his party is democratic and eschews the politics of extremism. He said his party was the driving force behind improved relations with India before he was ousted by Musharraf's coup.

Although American officials have expressed no public worries about this week's turmoil, the U.S. representative in the Punjab capital of Lahore visited Sharif's villa within hours of the court decision. Sharif's spokesmen declined to give details of the private meeting, and U.S. officials would not comment.

An experienced operator in Pakistan's hard-fought politics, Sharif already had urged his supporters to take to the streets to press for the return of the Supreme Court chief justice who was removed by Musharraf in 2007.

Justice Iftikhar Mohammed Chaudhry had questioned the legality of Musharraf's presidency as well as a deal that quashed corruption allegations against Zardari and his wife, former Prime Minister Benazir Bhutto, who was assassinated before last year's elections.

Chaudhry's ouster inspired Pakistan's largely secular civic groups to stage months of demonstrations that eventually pressured Musharraf to step down as the United States distanced itself from him.

Sharif predicts a similar outpouring of support from lawyers and other groups to back his party, which is the country's second largest political movement and which worked in an uneasy alliance with Zardari's bloc to push out Musharraf.

After the interview, thousands of Sharif supporters thronged peacefully along Lahore's main boulevard, waving his party's green flags and chanting "Go, Zardari, go!"

Rioting flared elsewhere for a third consecutive day, with police swinging batons and firing tear gas at stone-throwing youths among hundreds of people who blocked the six-lane highway between the capital, Islamabad, and the nearby city of Rawalpindi.

Protesters tore down advertising billboards, smashed street lights and blocked traffic with burning tires.

"If anybody thinks that they can make politics without Nawaz Sharif in this country, he is very much mistaken," said Raja Nasir Mahfoz, a middle-aged man in the crowd.

Paramilitary police carrying assault rifles stood guard along the highway, where traffic was halted for hours, but didn't intervene.

Police official Saqib Sultan said about 10 people were arrested. There were no reports of injuries.

Analysts say the political infighting will probably bog down Pakistan's ruling elite, leaving it unable to focus on improving the conditions for its mainly poor 170 million people.

Debilitating power struggles in the 1990s between Sharif and Zardari's slain wife, Bhutto, helped drive Pakistan to the brink of bankruptcy and paved the way for Musharraf's 1999 coup.

Without referring to his role in the current crisis, Sharif echoed those fears. "Pakistan is facing big problems ... now the pressures are mounting on Pakistan," he said.

Ties between Sharif and Zardari have worsened in recent months. Their shaky alliance foundered soon after Zardari became president, when he reneged on a promise to reinstate the ousted Supreme Court chief justice.

Sharif said there would be no reconciliation with Zardari unless he reinstates Chaudhry.

"It was Mr. Musharraf who declared martial law on the judges, the judiciary and on parliament, and it is now Mr. Zardari who has declared martial law on democracy," Sharif said.

He alleged Zardari did not want to see Chaudhry back in the Supreme Court out of fear he would re-examine the old corruption cases.

"Mr. Zardari's agenda is in contrast with the national agenda," he said.