Two Pakistani officials expelled by India over spying allegations have returned home, a Pakistan embassy spokesman said, as the nuclear-armed rivals wrangle over the claims.

The two staff members of the Pakistani High Commission in New Delhi, whose names have not been disclosed, returned to Pakistan via the Wagah border crossing, a Pakistan embassy spokesman said on Monday.

Meanwhile, Pakistan summoned India’s charge d’affaires in Islamabad to express its “condemnation” of the expulsion order.

Pakistan’s foreign ministry called the allegations “baseless” and said New Delhi’s action was a “clear violation” of the Vienna Convention on diplomatic relations.

On Sunday, the Indian government said the officials had been detained for “indulging in espionage activities” and given 24 hours to leave the country.

“Two [Pakistani] officials were apprehended on Sunday by Indian law enforcement,” India’s foreign ministry said in a statement, declaring them “persona non grata”.

Pakistan’s foreign ministry on Sunday condemned India’s decision in a statement, saying the two were lifted by Indian authorities on “false and unsubstantiated charges”.

“They were, however, released on intervention by the High Commission. We condemn the detention and torture as well as threatening and pressuring of diplomatic officials to accept false charges,” it said.

India and Pakistan routinely expel each other’s diplomats on spying charges. Pakistan is now expected to respond by expelling Indian High Commission officials in Islamabad in a tit-for-tat action.

India and Pakistan have a long-running dispute over Kashmir, which was split between them in 1947 when they gained independence from the UK.

The South Asian neighbours have fought three wars against each other since independence, including two over Kashmir.

Kashmir became a bigger source of tension in the relations between the regional powers after New Delhi last year scrapped the Muslim-majority Himalayan region’s semi-autonomous status and imposed a curfew to quell unrest.

Rebel groups in Indian-administered Kashmir have battled for decades for the region’s independence or its merger with Pakistan and enjoy broad popular support.

The fighting has left tens of thousands dead, mostly civilians, since 1989. India has more than 500,000 troops stationed in Kashmir.

Source: Al Jazeera