Islamabad: Three German nationals have been arrested in northwest city of Peshawar on Saturday on suspicion of engaging in "illegal" activities, police said.
Police officer Mian Saeed said the German citizens were being questioned for their "illegal" stay and for running an office in Peshawar, the capital of Khyber-Pakhtunkhwa province.
Police and personnel of security agencies raided a house in the posh University Town area and took the Germans into custody, Saeed told reporters.
The Germans had been running an office but had failed to produce any documents that showed they had been granted permission by Pakistani authorities to do so.
The arrested foreigners had recently moved to Peshawar and opened their office, which was sealed by police.
Another police officer said the Germans had told investigators that they opened the office for "coordination" between the two countries.
They also said they had been monitoring German-funded development projects.
"But they failed to present any documentary proof," the police officer said.
Police said some Pakistanis working with the Germans were also arrested.
The German nationals are likely to be sent to Islamabad for further investigation or to be handed over to the German embassy, security sources said. There was no word from the German embassy.
Footage on television showed police vehicles standing outside the home of the Germans in Peshawar. Several foreign missions and NGOs have offices in the area.