India shut its airspace to Pakistani airlines on Wednesday, the government said, days after its nuclear-armed neighbour banned Indian airlines from flying over its territory following the killing of 26 men in an attack on tourists in Kashmir.

The ban will last from April 30 to May 23, the Indian government said in a notice.

Pakistan’s Prime Minister Shehbaz Sharif told US Secretary of State Marco Rubio in a phone call on Wednesday evening that he “categorically rejected Indian attempts to link Pakistan to the incident,” Sharif’s office said in a statement.

He called for a transparent, credible and neutral investigation and urged the US to impress upon India to “dial down the rhetoric and act responsibly,” it added.

India’s foreign ministry did not immediately respond to a request for comment.

The impact of the ban on Pakistan’s airline industry is likely to be smaller than on India’s since only Pakistan International Airlines operates routes to Kuala Lumpur using Indian airspace.

Last week, Pakistan closed its airspace to Indian-owned or operated airlines, suspending all trade including through third countries and halting special South Asian visas issued to Indian nationals.

PIA, the national carrier, said on Tuesday it had decided to avoid Indian airspace in the wake of rising bilateral tensions.

Pakistan said on Wednesday it has “credible intelligence” that India intends to launch military action soon, as tensions between the nuclear-armed neighbours escalate following the deadly attack on tourists.

India has identified the three attackers, including two Pakistani nationals, as “terrorists” waging a violent revolt in Muslim-majority Kashmir. Islamabad has denied any role and called for a neutral investigation.

Since the attack, the nations have unleashed a raft of measures against each other, including suspending the Indus Water Treaty.