PESHAWAR: Seven US citizens were stopped by security officials from crossing the Peshawar toll plaza without a No Objection Certificates on Wednesday, DawnNews reported.

The US embassy has expressed serious concern over the incident, DawnNews reported.

Security officials said the foreigners were traveling in three cars and it was the second time they had attempted to enter without a NOCs.

They are required to obtain a NOCs from the relevant ministry before entering into Peshawar, said security officials.