Pakistan’s aviation authority said on Friday it would extend a ban on Indian airlines using its airspace for another month, after the worst violence between the nuclear-armed rivals in decades.

The ban was announced on April 24 as both sides traded diplomatic tit for tat measures that spilled into a four-day military conflict.

More than 70 people were killed in missile, drone and artillery fire until a ceasefire was announced on May 10.

“No flight operated by Indian airlines or operators will be allowed to use Pakistani airspace,” Pakistan’s Civil Aviation Authority said in a statement, adding that the ban had been extended until early morning on June 24.

“This ban will also apply to Indian military aircraft.”

India had returned in kind with a ban in late April, due to run until June 23.

The conflict was sparked by a deadly attack on tourists in Indian-administered Kashmir that New Delhi blamed Islamabad for backing.

Muslim-majority Kashmir is claimed in full by both countries, which have fought multiple wars over the Himalayan territory since their 1947 independence from Britain.

Pakistan’s decision to close its airspace to carriers from its neighbour has seen journeys from India to Central Asia, Europe, and North America take up to two hours longer.

And the extra flying time may eventually make flights more expensive.

Indian government data shows that when Islamabad closed its airspace in 2019 — after New Delhi hit it with airstrikes in response to an attack in Kashmir — domestic airlines saw a financial cost of nearly 5.5 billion rupees ($64.3 million) during the nearly five-month-long shutdown.