The British Foreign and Commonwealth Office (FCO) has advised its citizens to review their planned trips to Pakistan in view of the volatile security situation in the country.
"There is a high threat of terrorism, kidnapping and sectarian violence throughout Pakistan," Dawn online quoted an FCO travel advisory as saying Monday.
The warning, also released from British High Commission in Islamabad, includes travel plans of diplomats and official delegations.
"Violent clashes have occurred between the police and demonstrators at the large political protests in central Islamabad," it said.
"The police are restricting access to Islamabad's Red Zone (government sector and diplomatic enclave). Expect disruption to travel on other roads in and around Islamabad. You may also experience disruption to road travel in other cities, including Lahore."
In addition to Islamabad, the travel advisory also cautioned British citizens to review their travel to other parts of Pakistan, including Sindh and Balochistan.