Pakistani opposition leader Nawaz Sharif has been placed under house arrest.Officials from the former prime minister’s party said the move came hours before he was due to address a protest rally. Sharif has backed a campaign led by anti-government lawyers and had vowed to lead part of their march to Islamabad. His home in Lahore has now been virtually sealed off. Similar restrictions have reportedly been imposed on several other opposition leaders including former cricketer Imran Khan. Earlier, Pakistan’s government said it would seek a review of a Supreme Court ruling that barred Sharif and his brother from elected office.