Pakistan's interior minister Friday said the government was ready to throw out more foreign aid groups, a day after Save the Children were expelled for "working against the country".

Chaudhry Nisar Ali Khan said parliament was debating whether to expose what he said were the "many" foreign non-governmental organisations (NGOs) bent on undermining Pakistan.

Police and government officials sealed the Islamabad offices of Save the Children on Thursday, but gave no specific details of what the group was alleged to have done.

Pakistan has toughened its policies towards international aid groups in recent years, accusing them of being covers for spying operations and has repeatedly warned them to restrict their activities, vowing stern action for any "suspicious" activity.

"Many NGOs are working against Pakistan and we are deliberating on exposing them in the parliament," Nisar told reporters on Friday.

"Non-Government Organisations working against the country's national interest will not be allowed to continue their work in Pakistan."

Aid groups have complained in recent years that increasing government restrictions on their activities has hampered their efforts to help vulnerable people in a country which still has huge numbers who live in poverty.

They say their work in so-called "sensitive" areas such as southwestern Baluchistan, the country's poorest, least developed province, have been particularly affected.

Without naming any organisations, Khan said some NGOs had been operating without proper regulation and had worked in Baluchistan when they had permission only to work in Islamabad.

In 2012 the government expelled the expat staff of Save the Children, which has worked in Pakistan for over 35 years and employs 1,200 Pakistanis.

That move came after Pakistani intelligence services accused the charity of links to doctor Shakeel Afridi, who the CIA allegedly used to carry out a fake vaccination programme as they searched for Al-Qaeda chief Osama bin Laden.

Save the Children has always vehemently denied any link to either Afridi or the CIA.