On May 7th India launched Operation Sindoor claiming to have hit "terrorist infrastructure", targeting terrorist organizations including the Jaish-e-Muhammad (JeM) and Lashkar-e-Tayabba (LeT). JeM, an armed group based in Pakistan, claimed responsibility for a suicide bombing in Februart 2019 in Pulwama in Indian-adminstered Kashmir which killed 40 Indian paramilitary soliders.
The late-night missile strikes that hit six Pakistani sites resulted in at least 26 civilian deaths and 46 injured. According to BBC the relatives of Masood Azhar, chief of JeM, were killed in the strike in Bahawalpur.
For four days Pakistan and India fought each other with firings on the Line of Control, the border separating Indian-adminstered Kashmir and Pakistani-adminstered Kashmir. India targeted three airbases in Pakistan on May 10th after which Pakistan launched Operation Bunyan-um-Marsoos claiming to have India's power grid, airfields and posts across the LoC amongst other sites.
Amid attacks from both ends, talks continued between both the countries, mediated by the US. On May 11, President Donald Trump announced that both India and Pakistan agreed to an immediate ceasefire.
This was the first time in decades that the two nuclear countries were at the brink of all-out war.