What were the two neighboring Asian countries conducted testing of nuclear weapons for the first time in 1998?

In 1998, India and Pakistan conducted nuclear weapons tests for the first time, marking a significant escalation in their long-standing rivalry. India's tests, known as Operation Shakti, were conducted in May 1998, followed by Pakistan's tests, named Chagai-I, shortly thereafter. These developments drew international concern over nuclear proliferation in South Asia and heightened tensions in the region.