After India accused a Pakistan High Commission official of espionage on Thursday, Islamabad ordered Indian diplomat Surjeet Singh to leave the country and declared him persona non grata (an unacceptable or unwelcome person). Singh has been asked to leave Pakistan in 48 hours. “The activities of Surjeet Singh in Islamabad were in violation of Vienna Convention and established diplomatic norms,” a statement from Pakistan’s foreign office said.

Hours earlier, India had declared Pakistani diplomat Mehmood Akhtar persona non grata after he was questioned at a police station in Chanakyapuri, Delhi's diplomatic enclave, for allegedly possessing highly-classified defence documents. Ministry of External Affairs officials said Pakistani High Commissioner Abdul Basit was summoned and informed that Akhtar had been declared persona non grata for espionage activities. Akhtar was given 48 hours to leave India.

Joint Commissioner (Crime) of Delhi Police Ravindra Yadav had said, “The official said he is an Indian citizen and also showed a fake Aadhaar card.” It was later established that Akhtar was a Pakistani High Commission staffer. Officials also said they had arrested two men from Rajasthan – Maulana Ramzan and Subhash Jangir – for leaking the documents to Akhtar.

According to Yadav, Akhtar had been an officer in the Pakistan Army's Baloch regiment who was later hired by the Inter-Services Intelligence. He worked in the high commission's visa department, the official said, adding that those involved had been carrying out the espionage activities for at least 18 months, and their movements had been monitored for the past six months.

However, Abdul Basit had denied India's accusations and had, instead, accused the country of manhandling a Pakistani staffer. He said the high commission "never engages in activity incompatible with its diplomatic status". Pakistan has also accused India of violating the Vienna Convention, an international agreement that sets parameters for diplomatic relations. India's MEA spokesperson Vikas Swarup in his statement said Islamabad's denial had become "quite characteristic", ANI reported.

Documents recovered from the spies from Rajasthan included papers on deployment of defence personnel, maps of where Border Security Force officers had been stationed and visa-related documents.

In November 2015, five people were arrested after a syndicate of spies associated with Pakistani intelligence was exposed. A few employees of the Pakistan High Commission had come under the radar after the operation.

Akhtar's detention comes amid strained relations between India and Pakistan, which worsened since the militant attack on the Army's camp in Kashmir's Uri sector. Several security personnel have lost their lives in cross-border firing on both sides of the Line of Control. People living in the affected area have also been forced to migrate to safer locations.s