Benazir Bhutto, the Pakistani opposition leader, was put under house arrest today ahead of a major protest, a security official said.

Benazir Bhutto, the Pakistani opposition leader, was put under house arrest today ahead of a major protest, a security official said.

Police, backed by armoured vehicles, surrounded her Islamabad home.

The move came amid a broader crackdown on Bhutto supporters, who were planning to rally near Islamabad against President General Pervez Musharraf's emergency rule.

Bhutto's party said some 5,000 of its supporters have been rounded up in the last three days, and riot police were out in force in Rawalpindi, the city where today's rally was to take place.

Later, Information Minister Tariq Aziz said Bhutto was not formally under house arrest, but explained: "We will not allow any leader to carry out any rally. The law is equal for everybody and anyone violating it will be dealt with accordingly."

Outside Bhutto's home in an upscale Islamabad neighbourhood, dozens of police, some in riot gear, had taken up positions, laying barbed wire and erecting barriers.

"She's not going anywhere today," said an officer.

Bhutto supporters condemned the move.

"It shows the government is scared of Benazir Bhutto's popularity, and it does not want her to be among the masses," said close aide Babar Awan.

He added that the leadership of her Pakistan People's Party, the country's largest party, would try to reach Rawalpindi for the protests.