Pakistan has protested the expulsion of two of its embassy officials in India, which accused them of spying.
India's Foreign Ministry said that the two officials were detained on May 30 for 'indulging in espionage activities' and given 24 hours to leave the country.
Pakistan on June 1 summoned India's charge d'affaires in Islamabad, saying the accusations were "baseless."
In a statement, the Foreign Ministry said India's decision was a "clear violation" of "diplomatic norms."
Pakistan also recalled its ambassador from New Delhi and sent back the Indian envoy.
The row comes amid escalating tensions between the two nuclear-armed rivals over the disputed Himalayan region of Kashmir.
Muslim-majority Pakistan and Hindu-led India have fought two wars over control of Kashmir.
Officials in India-administered Kashmir said on June 1 that three men were killed after a shootout near the de facto border known as the Line of Control (LoC).
India accuses Pakistan of funding militant groups fighting Indian troops, a claim Islamabad denies.
Based on reporting by AFP and dpa
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