An attack on tourists in India’s Himalayan territory of Kashmir this week sparked a new crisis between nuclear armed South Asian neighbours India and Pakistan, with New Delhi blaming militants with “cross-border linkages” for the killings.

Here is a look at the tit-for-tat measures the two countries have announced in the aftermath of the violence.

WHAT HAPPENED?

Suspected militants opened fire in the Baisaran Valley, a popular tourist attraction in Kashmir’s Pahalgam area, on Tuesday afternoon, killing 26 people and wounding several others before fleeing into the surrounding pine forests.

WHY DOES INDIA SAY PAKISTAN IS INVOLVED?

The two countries both claim Kashmir in full, but rule it in part. India has long accused Pakistan of helping Islamist separatists who have battled security forces in its part of the territory - accusations Islamabad denies.

Indian officials say Tuesday’s attack had “cross-border linkages”. Kashmiri police, in notices identifying three people “involved” in the violence, said two of them were Pakistani nationals. India has not elaborated on the links or shared proof.

HOW HAS PAKISTAN RESPONDED?

Pakistan said India’s accusations were made without any “credible investigation” or “verifiable evidence”, saying they are “frivolous” and “devoid of rationality”.

It has also called on India to refrain from a “reflexive blame game” and to take responsibility for its “failure to provide security” to people.

WHAT MEASURES HAVE THE COUNTRIES TAKEN?

* Both countries have closed the only open land border they share, and suspended special South Asian visas that enabled people to travel between them.

* They have declared each other’s defence advisors in missions in New Delhi and Islamabad persona non grata, and reduced the strength of their embassies.

* India has suspended a critical treaty that regulated the sharing of water from the Indus River and its tributaries. Pakistan has warned that any attempt to stop or divert the water will be considered an act of war and met with “full force”.

* Pakistan has paused all bilateral agreements and suspended all trade with India, including to and from any third country.

* Pakistan has closed its airspace to all Indian-owned and Indian-operated airlines.