Demonstrators held rallies in Pakistan and the UK after Indian missile strikes on Pakistan and Pakistan-administered Kashmir killed at least 31 civilians, including children and women, and wounded 57 others.

Pakistan said it will "avenge" those killed by Indian air strikes.

"We make this pledge, that we will avenge each drop of the blood of these martyrs," Pakistani Prime Minister Shehbaz Sharif said in an address to the nation late on Wednesday.

India's army says it destroyed nine so-called "terrorist camps" in Pakistan, while Islamabad says it shot down five Indian fighter aircraft and several drones.

There was no comment from India, but three planes fell onto villages in India-administered Kashmir, according to local police and residents.

In Pakistan, businessman Umbreen Mahar said: "No one in today's world wants to favour war. But if India continues to slander us and then attack, Pakistan has the right to retaliate and defend its sovereignty."