The US has supported India’s right to “self defence” against cross-border terrorism after an attack claimed by Pakistan-based militants killed at least 44 police officers in the disputed territory of Kashmir.

In comments that will please Indian hawks but also raise fears that tensions between India and Pakistan could escalate yet further, US national security advisor John Bolton reportedly told his counterpart in Delhi, that America “offered all assistance to India” to bring the perpetrators of the attack to justice.

Mr Bolton and Ajit Doval also “resolved to hold Pakistan to account for its obligations under UN resolutions”, India’s foreign ministry said in a statement.

The development came after 44 members of an Indian paramilitary police force were this week killed in a car bomb attack on a convoy at Pulwama, near Srinigar. Responsibility for the attack was claimed by Jaish-e-Mohammad (JeM), a group that operates out of Pakistan and was founded by Masood Azhar.

India on Friday claimed it had “incontrovertible evidence” Pakistan had a “direct hand” in the attack. Finance minister Arun Jaitley said India would initiate “all possible diplomatic steps” to “ensure the complete isolation from the international community of Pakistan, of which incontrovertible evidence is available of having a direct hand in this gruesome terrorist incident”.

Fire on the streets as Indians react to the Pulwama bombing attack Show all 13 1 /13 Fire on the streets as Indians react to the Pulwama bombing attack Fire on the streets as Indians react to the Pulwama bombing attack Indian muslims in Mumbai burn posters of Pakistani prime minister Imran Khan, center, and Hafiz Saeed, chief of Pakistani religious group Jamaat-ud-Dawa, during a protest against Thursday's attack on a paramilitary convoy in Kashmir that killed at least 40 AP Fire on the streets as Indians react to the Pulwama bombing attack Policeman walk past vehicles set on fire in Jammu by a mob during a protest against Thursday's attack on a paramilitary convoy AP Fire on the streets as Indians react to the Pulwama bombing attack Vehicles are set on fire in Jammu during protests following the attack AP Fire on the streets as Indians react to the Pulwama bombing attack Indian Muslims hold a protest in Mumbai the day after the terrorist attack AFP/Getty Images Fire on the streets as Indians react to the Pulwama bombing attack Mourners gather for the cremation of Central Reserve Police Force soldier Mahesh Yadav, who was killed in Thursday's bombing in Kashmir AP Fire on the streets as Indians react to the Pulwama bombing attack Protestors in Jammu throw stones during a clash between communities while protesting against Thursday's attack on a paramilitary convoy that killed at least 40 in Kashmir AP Fire on the streets as Indians react to the Pulwama bombing attack Indian police men keep vigil next to a barbed wire fencing during the third day of curfew in Jammu AP Fire on the streets as Indians react to the Pulwama bombing attack India's ruling Bharatiya Janata Party workers in Mumbai burn a symbolic effigy of Pakistan as part of protest against Thursday's attack on a paramilitary convoy in Kashmir, AP Fire on the streets as Indians react to the Pulwama bombing attack Central Reserve Police Force (CRPF) soldiers pay tribute to their colleague Maneswar Basumatary, who was killed in Thursday's bombing in Kashmir AP Fire on the streets as Indians react to the Pulwama bombing attack Indian army soldiers patrol during a curfew in Jammu on February 16, 2019 AFP/Getty Images Fire on the streets as Indians react to the Pulwama bombing attack A crowd carries a victim's coffin during a cremation ceremony AFP/Getty Images Fire on the streets as Indians react to the Pulwama bombing attack A relative of Indian Central Reserve Police Force (CRPF) trooper Sudip Biswas mourns over his coffin at Kolkata airport AFP/Getty Images Fire on the streets as Indians react to the Pulwama bombing attack Mourners gather for the cremation of Central Reserve Police Force soldier Mahesh Yadav, who was killed in Thursday's bombing in Kashmir AP

He said India was to strip Pakistan of its “most favoured nation status” , a move that reportedly increased tariffs on Pakistani goods by 200 per cent.

Pakistan has denied it had any role in Thursday’s attack and accused India of pointing the finger of blame without conducting a proper investigation. Pakistan’s foreign secretary Tehmina Janjua said in a statement after meeting foreign ambassadors, there was: “A familiar Indian pattern of immediate and reflexive assignment of blame on Pakistan without investigations.”

Pakistan has long been accused of harbouring militant groups the nation’s military historically saw as part of its defence against India. Over the years, its intelligence forces have supplied weapons and logistical support to militants to carry out cross-border attacks in Kashmir, a long-disputed region that each country lays claim to and controls part of it.

In recent years, Pakistan has said it has dropped its support for such militants, despite its failure to bring to justice figures such as Hafiz Saeed, the founder of the militant group Lashkar-e-Taiba, which has been blamed for the 2008 Mumbai attacks that left more than 160 people dead.

Just how to control such militants is a major challenge for prime minister Imran Khan, who was elected last year. Many believe the leader of the Pakistan Tehreek-e-Insaf party, won the election with at least the tacit approval of the country’s powerful military, making it harder for him to crack down on militants that may have links to the armed forces or intelligence services.

Tensions between India and Pakistan, two nuclear-armed nations which have gone to four on four occasions since the two nations secured their independence from Britain in 1947, have worsened in the days since the attack, despite Islamabad’s insistence it had nothing to do with it.

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India’s population is majority Hindu, while Pakistan is overwhelmingly Muslim.

The situation is made more challenging by the fact India is due to hold a general election in May, heaping pressure on India’s prime minister Narendra Modi, as his country looks to how he responds to the attack, the deadliest of its kind in years.

Over the weekend, the bodies of members of the central reserve police force killed in the bombing, were returned to villages and towns across the country for funeral rites.