Political tensions have heightened in Pakistan after the country's Supreme Court barred top opposition leader and former prime minister Nawaz Sharif from elected office. The court ruling also has effectively dismissed Sharif's younger brother as chief minister of the politically important Punjab Province.
The Pakistani Supreme Court ruled on appeal against a lower court's decision that barred Nawaz Sharif from contesting last year's parliamentary elections because of a prior criminal conviction.
The country's highest court was also looking into allegations of irregularities in the election of Sharif's younger brother, Shahbaz Sharif, to the legislative assembly of Punjab. The Supreme Court decision means that Sharif's brother cannot continue as head of the provincial government.
The decision against top leaders of the country's main opposition party, Pakistan Muslim League-N, has outraged its supporters and activists. Angry protesters took to the streets in several cities, including the capital Islamabad and torched tires to block roads, but there are no reports of casualties.
Demonstrators chanted anti-government slogans and accused the federal government under President Asif Ali Zardari of influencing the court to seek disqualifications of their leaders.
A senior member and spokesman for Sharif's political party, Ahsan Iqbal, alleged that his leaders were punished for their campaign aimed at seeking removal of "unconstitutional" polices that former military ruler Pervez Musharraf had introduced.
"This is a coup against democracy it is a coup against PML-N's [Pakistan Muslim League-N] elected government in Punjab just like general Musharraf staged a coup against judiciary. And this shows that there is no change," said Iqbal. "Mr. Zardari is pursuing agenda of General Musharraf."
Following elections last year, Sharif's political party joined the ruling coalition headed by the Pakistan Peoples party of President Asif Zardari. But Sharif quit the alliance after Mr. Zardari refused to reinstate judges fired by former president Musharraf.
Since then, political tensions have risen and Sharif has already announced his support for the so-called "long march" rally next month by lawyers. The protest campaign is meant to press President Zardari to reinstate the ousted judiciary. The lawyers' movement has staged major protests across Pakistan since 2007, playing a key role in driving General Musharraf from power.
Sharif and most opposition politicians have rejected existing judges of higher courts as "puppets" of President Zardari.
Government officials have rejected opposition criticism, saying the government or President Zardari have nothing to do with the Supreme Court ruling.
Critics say the Supreme Court decision to disqualify popular leaders of Pakistan's main opposition party is likely to deepen political instability in the country, which is already facing a rising threat of militancy in its northwestern regions.
There are also fears growing political turmoil could deepen the economic crisis Pakistan is facing.