India said it was striking infrastructure used by militants.
The Pakistan Air Force (PAF) said it shot down five Indian jets in response.
The Indian army later said three civilians were killed in shelling by Pakistani troops in Indian-controlled Kashmir.
It said in a statement the Pakistani army “resorted to arbitrary firing,” including gunfire and artillery shelling, across the Line of Control, the de facto border that divides disputed Kashmir between the two countries, and their international border.
The Indian army was “responding in a proportionate manner,” it said.
Tensions have soared between the nuclear-armed neighbours since last month’s massacre of tourists in Indian-Kashmir. India has blamed Pakistan for backing the militant attack, which Islamabad has denied.
Pakistan’s Prime Minister Shehbaz Sharif condemned Wednesday’s air strikes and said the “deceitful enemy has carried out cowardly attacks” and that his country would retaliate.
“Pakistan has every right to give a robust response to this act of war imposed by India, and a strong response is indeed being given,” Sharif said.
Sharif has convened a meeting of the National Security Committee for Wednesday morning.
The missiles struck locations in Pakistani-Kashmir and in the country’s eastern Punjab province. One hit a mosque in the city of Bahawalpur in Punjab, where a child was killed.
Pakistan’s military spokesperson said India launched attacks at six different locations, resulting in the deaths of eight people and injuries to 38. Other locations hit were near Muridke in Punjab and Kotli in Pakistan-controlled Kashmir.
India’s Defense Ministry said at least nine sites were targeted “where terrorist attacks against India have been planned.”
“Our actions have been focused, measured and non-escalatory in nature. No Pakistan military facilities have been targeted,” the statement said, adding that “India has demonstrated considerable restraint in selection of targets and method of execution.”
Stephane Dujarric, the United Nations spokesperson, said in a statement late on Tuesday that Secretary-General Antonio Guterres was “very concerned about the Indian military operations across the Line of Control and international border” and called for maximum military restraint from both countries.
“The world cannot afford a military confrontation between India and Pakistan,” the statement read. (AP)
