The 2007 Samjhauta Express bombings was a terrorist attack that occurred around midnight on 18 February 2007 on the Samjhauta Express, a twice-weekly train service connecting Delhi, India, and Lahore, Pakistan. Bombs were set off in two carriages, both filled with passengers, just after the train passed Diwana near the Indian city of Panipat, 80 kilometres (50 mi) north of New Delhi. 70 people were killed in the ensuing fire and dozens more were injured. Of the 70 fatalities, most were Pakistani civilians. The victims also included some Indian civilians and three railway policemen.

Investigators subsequently found evidence of suitcases with explosives and flammable material, including three undetonated bombs. Inside one of the undetonated suitcases, a digital timer encased in transparent plastic was packed alongside a dozen plastic bottles containing fuel oils and chemicals. After the bombing, eight unaffected carriages were allowed to continue onwards to Lahore with passengers. Both the Indian and Pakistani governments condemned the attack, and officials on both sides speculated that the perpetrators intended to disrupt improving relations between the two nations, since the attack came just a day before Pakistani Foreign Minister Khurshid Mahmud Kasuri was to arrive in New Delhi to resume peace talks with Indian leaders.

India's National Investigation Agency (NIA) charged eight people in the terrorist attack, including Swami Aseemanand, a Hindu cleric formerly affiliated with the Rashtriya Swayamsevak Sangh. While Aseemanand was released on bail, three persons charged in the case are absconding, and three others are in prison. The alleged mastermind, Sunil Joshi, was killed in 2007. In 2019, an NIA court acquitted all the accused.

It has been allegedly linked to Abhinav Bharat, a Hindu fundamentalist group in India. Allegations were also concurred on Lashkar-e-Taiba (LeT), an Islamic fundamentalist terror group in Pakistan. A United States report declared Arif Qasmani to be involved in the attack. Consequently, he was designated as a Specially Designated Global Terrorist by the United States and designated by the Al-Qaida and Taliban Sanctions Committee of the United Nations Security Council for facilitating the LeT in "the July 2006 train bombing in Mumbai, India, and the February 2007 Samjota Express bombing in Panipat, India."

Questions were raised over a Pakistani national who was arrested after the bombings for not carrying valid papers and was seen as suspicious by the investigators, but was discharged within 14 days according to a statement of the first investigation officer assigned to the case. A court order had noted the statement of the police that no proof had been found against him, which was also stated later by one of the senior officers.

A narco-analysis test was conducted on SIMI's leaders Safdar Nagori, Kamruddin Nagori and Amil Parvez who had stated about Abdul Razzaq's involvement in the blasts and him informing Safdar about it. Times Now had broadcast a video of the test in 2017. The later statements of Swami Aseemanand of Sunil Joshi telling him of involvement of his men in the blast had caused confusion for the investigators. One of the investigating officers stated in 2016 that they had investigated the Islamists including Safdar but didn't find them involved. Razzaq who had been in prison since 2005 had been interrogated and had brought Qasmani to the notice of Intelligence Bureau as a key Lashkar financier. He was questioned regarding the case, but no evidence of his involvement were found. Some officers had also questioned the reliability of narco-analysis.

Since their formation resulting from the Partition of India in 1947, India and Pakistan have had a conflict-ridden relationship. In their plan for the partition, the British allowed all 565 princely states to decide which country they wanted to join. Most Hindu-majority princely states acceded to the Republic of India, while most Muslim-majority princely states joined the Dominion (now Islamic Republic) of Pakistan. The decision made by the leaders of some of these princely states has been a source of conflict and tension between the two countries. Kashmir is one of these princely states—its population was mostly Muslim, but the Hindu ruler Hari Singh of the state decided to join India. The countries have fought four wars over this disputed region: the Indo-Pakistani War of 1947, the Indo-Pakistani War of 1965, the Indo-Pakistani War of 1971 (resulting in the formation of Bangladesh), and the Kargil War in 1999.

Since the 1980s, militants in Jammu and Kashmir have targeted attacks on civilians, members of the government and the Indian Army. Some groups, like the Islamist militant organisations Lashkar-e-Taiba and Jaish-e-Mohammed, believe that Kashmir should be integrated into Pakistan, while others—such as the Jammu Kashmir Liberation Front—believe it should become an independent state. All told, thousands of civilians have died due to the insurgency.