NEW DELHI — At least five Indian civilians and four Pakistani civilians were killed by overnight shelling along the disputed Indian-Pakistani border, both countries said on Monday, in fighting that brought an end to a monthlong lull in cross-border fire.

Three men and two women were killed and more than 20 people hospitalized with injuries after a night of heavy mortar fire, said Devender Singh, the police chief in a district of the Indian state of Jammu and Kashmir, which includes Arnia, a village that was hit in the shelling.

The Pakistani Ministry of Foreign Affairs said in a statement that two children and a woman in the village of Dharmala, as well as a man in Tulsipur, had been killed. Six other people were said to have been wounded in what Pakistan called “unprovoked firing” and a violation of a cease-fire agreement.

Each side blamed the other for the shooting. The Pakistani Foreign Ministry said that Islamabad had “lodged strong protest” to India through diplomatic channels.