Pakistan says it will avenge those killed by India’s missile strikes that New Delhi called retaliation for last month’s massacre of Indian tourists.

Tensions have risen between the nuclear-armed neighbors since an attack on Hindu tourists in Indian Kashmir last month.

The escalating conflict between India and Pakistan, two neighbors who have been rivals for decades, erupted in the early hours of Wednesday morning when New Delhi launched missiles across the border.

New Delhi controls around 172 nuclear weapons, according to the Arms Control Association. Pakistan has approximately 170 nuclear warheads. India and Pakistan, two nuclear-armed nations, saw a decades-old conflict reignite May 7 as a terror attack in the disputed region of Kashmir led India to carry out cross-border airstrikes.

India’s actions came in response to a deadly terror attack two weeks ago in Kashmir, a territory that it has long fought over with Pakistan.