Pakistani intelligence officials on Saturday night harassed India's Charge d' Affaires Sudhir Vyas and his wife by blocking several times the car in which they were travelling.

Describing the action as 'unprecedented', the Indian high commission on Sunday sent a note verbale to the Pakistan foreign office.

"The CDA was blockaded before his residence and forcibly prevented from leaving on two occasions... he and his wife were to attend official diplomatic engagements at the Malaysian and Nepalese embassies yesterday," it said.

When the car, which was carrying an Indian flag, managed to leave the residence, it was, in an unprecedented action, forcibly stopped and boxed in by four vehicles and two motorcycles on the main roads of the town, it said.

While returning, intelligence personnel attempted to block the entrance gate to his residence by parking a vehicle in front.

The note said such harassment not only amounted to a 'clear attempt' on the part of Pakistani intelligence agencies to prevent Vyas from conducting his diplomatic duties, but also displayed a 'lack of normal courtesy to the national flag of this accredited mission'.

"This represents a grave violation of basic norms of diplomatic behaviour codified in international and bilateral conventions. This mission condemns such action and requests the ministry to direct the Pakistani intelligence agencies responsible to stop this harassment forthwith," it said.