Pakistan has said its laws were "violated" after Greece attempted to repatriate 30 migrants by putting them on a plane to Islamabad.
The migrants were prevented from leaving the chartered plane after it landed, with officials claiming they were "unverified deportees".
"On the interior minister's orders, the Federal Investigation Agency has not allowed these illegally deported people and the aircraft crew to leave the plane," the ministry said in a statement.
The charter plane later took off with the 30 still aboard, although a number of others that Pakistan deemed legitimate deportees were allowed to disembark.

Pakistani Interior Minister Nisar Ali Khan said: "Despite having settled all issues with the European Commissioner, Pakistani laws have been violated, which absolutely cannot be allowed.
It comes as migrants from Pakistan, Iran and other countries who were being prevented from crossing into EU states through Macedonia set up roadblocks in protest.

Groups of migrants used empty barrels, pieces of wood and metal to make a barrier about 120 metres (394 feet) from the Greek-Macedonian border.
Macedonia is only allowing people from Syria, Afghanistan and Iraq to cross as it considers everyone else to be economic migrants.
An estimated 50,000 Pakistanis travel legally to Europe for work each year. Last year, about 21,000 living there without permission were ordered to return to Pakistan, according to EU statistics.