According to Foreign Office spokesperson Nafees Zakaria, the government of Pakistan's decision was conveyed by Foreign Secretary Aizaz Ahmad Chaudhry to Indian High Commissioner Gautam Bambawale by summoning him on October 27, 2016. He said that the foreign secretary expressed deep concern over the activities of the Indian official that were in violation of the Vienna Convention and the established diplomatic norms. "The Foreign Secretary hoped that other members of the [Indian] High Commission would not indulge in the activities detrimental to Pakistan's national security," he added.
The decision came following a Pakistani official of the High Commission in New Delhi Mehmood Akhtar was briefly detained and released before he was asked to leave India by October 29 on the charges of espionage, the allegation Pakistan rejected as baseless.
"We reject the Indian allegations and deplore the Indian action which is indeed a violation of the Vienna Convention as well as the norms of diplomatic conduct especially in an already vitiated atmosphere. Pakistan High Commission has always been working within the parameters of international law and diplomatic norms. This act clearly reflects Indian actions to shrink diplomatic space for the working of Pakistan High Commission", said a Foreign Office statement on Thursday.
Indian government also rejected the charges levelled against its official of the High Commission in Islamabad and "regretted" the government of Pakistan's decision. "Government notes with regret the government of Pakistan's decision to declare Surjeet Singh, Assistant Personnel and Welfare Officer in the High Commission of India in Islamabad, persona non grata and expel him and his family members. No justification has been provided by the Government of Pakistan except for the completely baseless and unsubstantiated allegation that his activities were not in keeping with diplomatic norms", said a statement of the Indian External Affairs Ministry.