Pakistan has launched its retaliatory attacks — dubbed "Bunyan-un-Marsoos" operation — against India after New Delhi fired missiles at three air bases inside Pakistan.

"Bunyan-un-Marsoos operation has begun," the state-run media reported early on Saturday.

"Multiple locations in India are being targeted in the retaliatory attacks."

"Bunyan-un-Marsoos" translates to "solid structure" or "impenetrable wall."

Pakistan's military said the targets were an Indian Brahmos missile storage facility and airbases in Pathankot and Udhampur in India-administered Kashmir.

Indian air attacks are currently under way in Pakistan, Reuters news agency said, citing Indian military sources.

Loud explosions were heard at multiple places in Indian-controlled Kashmir, residents said.        

The explosions on Saturday were heard in the disputed region's two big cities of Srinagar and Jammu, and the garrison town of Udhampur.

Indian missiles

Ahead of Pakistani counter-strikes, India fired missiles at three air bases inside Pakistan but most of the missiles were intercepted, Pakistan’s army spokesman said.

It’s the latest escalation in a conflict triggered by a gun massacre last month that India blames Pakistan for.

Islamabad has denied any role and called for an international probe, a demand that India has rejected.

The Indian army said in a statement late on Friday that drones were sighted in 26 locations in Indian states bordering Pakistan and in Indian-controlled Kashmir, including region’s Srinagar main city.

It said the drones were tracked and engaged.

"The situation is under close and constant watch, and prompt action is being taken wherever necessary," the statement said.