Heavy rains brought down walls in parts of Uttar Pradesh on Friday, killing 13 people including nine labourers who were buried alive under the debris in the state capital.

The state government has announced financial assistance of Rs 4 lakh to the families of the deceased.

In Lucknow, an under-construction boundary wall of an Army enclave collapsed following overnight rains, leaving nine labourers dead and one injured, police said.

"Some labourers were living in huts outside an Army enclave in the Dilkusha area. Owing to heavy overnight rains, the boundary wall of the Army enclave collapsed," Joint Commissioner of Police (Law and Order) Piyush Mordia told PTI.

"We reached the spot around 3 am. Nine bodies were pulled out from the debris. One person was rescued alive," he said.

District Magistrate Suryapal Gangwar said the injured has been admitted to Dr Shyama Prasad Mukherjee (Civil) Hospital.

The deceased hailed from Jhansi district.

President Droupadi Murmu, Defence Minister Rajnath Singh, Uttar Pradesh Governor Anandiben Patel, Chief Minister Yogi Adityanath and Deputy Chief Ministers Keshav Prasad Maurya and Brajesh Pathak expressed grief over the loss of lives in the incident.

"I am deeply saddened by the news of death of people due to a wall collapse in Lucknow. My condolences to the bereaved families. I wish the injured a speedy recovery," Murmu tweeted in Hindi.

In Unnao district, four people including two children died in wall collapse incidents in Kantha and Chandpur Jhalihai villages.

In Kantha, three siblings -- Ankit (20), Ankush (4) and Unnati (6) -- died after a wall of their house collapsed due to overnight rains, said Additional District Magistrate (Finance and Revenue) Narendra Singh.

According to the villagers, the incident took place between 2 am and 3 am when the parents of the deceased had come out to assess the damage caused to their house due to rains.

In a similar incident, 66-year-old Bal Govind died in Chandpur Jhalihai village, Singh said.

The bodies have been sent for a post-mortem examination, officials said.

Chief Minister Adityanath has directed officials to provide financial assistance of Rs 4 lakh to the kin of each of the deceased, his office said in a tweet in Hindi.

In view of the heavy rains, Adityanath directed officials across districts to monitor relief work and ensure that financial help is provided to the affected swiftly, an official statement said.

Financial assistance should also be provided to those whose houses have been damaged or animals have died, he said.

The chief minister also ordered officials to conduct surveys to assess the damage caused to crops due to rains, the statement said.