US threatens to withhold aid as Pakistan swings from democracy to dictatorship

Elections due to take place in Pakistan in a matter of weeks could be postponed by a year, the government has announced, and it said 500 people had been detained at gunpoint after General Pervez Musharraf suspended the country's constitution and imposed martial law.

Dozens of other political opponents were on the run – among them the former cricketer-turned-politician Imran Khan – and human rights activists were rounded up as the authorities sought pre-emptively to stamp out opposition to General Musharraf's move to sack and arrest seven Supreme Court judges and invoke a state of emergency. The judges, including Chief Justice Iftikhar Chaudhry, were under house arrest while television channels remained off the air.

With Islamabad muted but calm the day after General Musharraf's televised midnight address to the nation claiming he was acting to prevent the country falling prey to terrorists, lawyers called for a general strike today and said they would be taking to the streets of several cities in protest.

Condoleezza Rice, the US Secretary of State, warned that billions of dollars of aid given to Pakistan would be reviewed as a result of the behaviour of its ally in the "war on terror".

General Musharraf's government said it could not say how long the state of emergency would last. It is clear, however, that the government's pronouncements come with questionable levels of honesty and accuracy. Just two days ago the government's Information Minister, Tariq Azim, insisted to reporters that "neither emergency nor martial law is being imposed". Yesterday, Mr Azim was present at a press conference where the Prime Minister, Shaukat Aziz, announced that hundreds of people were being held without charge and that the current parliament – due to be dissolved in days – might sit for another year.

Across Pakistan, people expressed a range of emotions ranging from anger to bewilderment at General Musharraf's decision to replace the Supreme Court justices just days before they were due to rule on the legality of his recent presidential election victory.

Although General Musharraf claimed he was acting to defend Pakistan against Islamic extremists, few saw it as anything other than an attempt to shore up his own position ahead of a court decision that could have ruled that his election victory was invalid.

"I think this is martial law. There is no television, no newspapers," said a woman walking in a park nestled beneath the Margalla Hills, which overlook Islamabad. "But what can we do, we are just ordinary people?"

Bushra Aitzaz Ahsan, the wife of the leading lawyer Aitzaz Ahsan, who was among those detained, said the Supreme Court justices had refused to support General Musharraf's suspension of the constitution. "Everything the government is doing is illegal and treasonable because the Supreme Court rejected the order," she said. Mr Ahsan was being held in jail and refused visitors.

The ousted Chief Justice was also being refused visitors. Swarms of armed police blocked off the road leading to his house and refused to let people pass.

As the world waits to see the response of the Pakistani people to General Musharraf's suspension of the constitution, focus will also be upon what messages the US sends to the military leader in the coming days.

While Washington, which has given more than $10bn (£5bn) to Pakistan in the six years since the September 11 attacks, urged General Musharraf not to invoke emergency powers, some observers questioned to what extent this move will genuinely trouble the Bush administration – especially if the suspension is relatively short-lived and parliamentary elections are held sooner rather than later.

Either way, the US has opened itself to serious questions about its policy of supporting General Musharraf at all costs and its willingness to turn a blind eye to some of government's more extreme actions. Ms Rice hinted that while US aid to Pakistan would be reviewed, much of it would almost certainly continue. "Some of the aid that goes to Pakistan is directly related to the counter-terrorism mission," she said, while in the Middle East. "We just have to review the situation."

Also of considerable importance will be the moves made in the next few days by the former prime minister Benazir Bhutto, head of the Pakistan People's Party and the woman who has perhaps the most to gain from elections, having previously come to a power-sharing arrangement with General Musharraf.

Will Ms Bhutto lead a populist campaign against General Musharraf – as she did against another military dictator, General Mohammed Zia-ul-Haq, when she first returned from exile in the mid-1980s – or will she bide her time, hoping that international pressure will lead to a vote?

The crackdown by the authorities targeted not just opposition politicians but human rights campaigners as well. Among those seized were Javed Hashmi, the acting president of the party of the former prime minister Nawaz Sharif; Asma Jahangir, chairman of the independent Human Rights Commission of Pakistan; and Hamid Gul, the former head of the country's main intelligence agency and a staunch critic of General Musharraf.

About 200 police with assault rifles and sticks stormed the human rights commission's office in Lahore. "They dragged us out, including the women. It's inhuman, undemocratic and a violation of human rights to enter a room and arrest people gathering peacefully there," the legal officer Mehbood Ahmed Khan told reporters.

General Musharraf's emergency order suspended Pakistan's 1973 constitution. Seven of the 17 Supreme Court judges immediately rejected the order, and only five agreed to take the oath of office under the new provisional constitution. Two new ordinances relating to the media were issued by Gen eral Musharraf. One bans live broadcasts of "incidents of violence and conflict" while the other imposes sentences of up to three years' jail for TV operators who "ridicule" the President, armed forces and other state bodies.