Pakistan is kicking out 18 international charities after rejecting their final appeal to stay in the country, a move that an aid group spokesperson said Thursday would affect millions of desperately poor Pakistanis and lead to the loss of tens of millions of aid dollars.

The majority of the shuttered aid groups are U.S. based, while the rest are from Britain and the European Union, according to a government list seen by The Associated Press. Among the organizations are World Vision, Plan International and Catholic Relief Services.

Another 20 groups are at risk of also being expelled after authorities a few months ago singled out some 38 international aid groups for closure without any explanation.

The development is the latest in a systematic crackdown on international organizations in Pakistan, with authorities using every bureaucratic excuse, such as discrepancies in visa and registration documentation, to target the organizations.

Aid workers as spies?

There is also a perception in Islamabad that the United States and European countries have secretly brought spies into Pakistan under the guise of aid workers.

On Thursday, Pakistan's Human Rights Minister Shireen Mazari said on Twitter the 18 groups that were asked to leave had spread disinformation.

"They must leave. They need to work within their stated intent which these 18 didn't do."

A Pakistani police officer stands guard outside a sealed office of international aid group Save the Children in Islamabad in June 2015. Most of the groups formally ousted Thursday had already ceased operations in the country. (Anjum Naveed/Associated Press)

Umair Hasan, a spokesperson for the Pakistan Humanitarian Foundation — an umbrella representing 15 of the charities — said those charities alone help 11 million poor Pakistanis and contribute about $175 million in assistance.

"No organization has been given a clear reason for the denial of its registration renewal applications," Hasan said.

Pakistan and its security forces are still stinging from a 2011 covert operation that involved a Pakistani doctor, an aid group and a vaccination scam to identify Osama bin Laden's home, aiding U.S. Navy Seals who tracked and later killed him.

Islamabad says the United States never notified it of the daring nighttime raid in the Pakistani garrison city of Abbottabad — just a few kilometres from Pakistan's top military academy — in advance, and that the mission that nabbed bin Laden invaded its sovereignty.

Many believe the sweeping crackdown on aid groups is the fallout from the CIA sting operation in which Pakistani doctor Shakeel Afridi, posing as an international aid worker, used a fake hepatitis vaccination program to try to get DNA samples from bin Laden's family as a means of pinpointing his location.

Afridi was subsequently arrested and remains in jail in northwestern Pakistan. Washington has repeatedly demanded his release.

Latest pushback against NGOs

The crackdown "simply marks the latest chapter in an ongoing effort to push back against foreign NGOs in Pakistan," said Michael Kugelman, deputy director of the Asia Programs at the Washington-based Wilson Center. "It's hard to overstate the significance of the hunt for bin Laden and the impact it had on Pakistani perceptions of foreign NGOs."

Hasan said the 18 expelled groups, with the exception of two that are still in court trying to overturn their ouster, have closed their operations in Pakistan.

The groups provided everything from education, to health care, to sanitary and clean water facilities, he said. Many worked in partnership with provincial governments, often supplementing meagre development budgets.

Now, local officials are being "told not to work with these" groups, added Hasan. "Government people up front will tell you they see the value of their work, but the decision has been taken."

Gen. Asif Ghafoor, a military spokesperson, denies any link between the closures of aid groups and the bin Laden operation, insisting they simply did not meet the criteria, though many had operated for decades in Pakistan.

Pakistan has cracked down on dissidents in recent months, and its numerous television channels and newspapers have faced increasing censorship, which has been criticized by international as well as national media watchdogs.

Maj.-Gen. Asif Ghafoor, a Pakistani army spokesperson, on Thursday denied any link between the NGOs' expulsions and a 2011 CIA sting operation designed to locate Osama bin Laden's home. (Anjum Naveed/Associated Press)

"Civil society space has shrunk," said Hasan. "Next, they will go after local organizations who receive international funding. It will seriously compromise the independence of organizations, their flexibility of how to operate, where to operate."

"These crackdowns on charities will deliver another blow to Pakistan's image," said Kugelman. "While Pakistan certainly isn't the only country to be curtailing the activities of charitable groups, the reputational impacts could be particularly strong because it has a pre-existing image problem."