NEW DELHI, May 1 (Xinhua) -- Indian Prime Minister Narendra Modi Saturday expressed grief over the loss of lives in a deadly fire in the western state of Gujarat that claimed 18 lives, officials said.

The fire broke out early Saturday inside a four-storeyed welfare hospital in Bharuch district, about 212 km south of Gandhinagar, the capital city of Gujarat.

"Pained by the loss of lives due to a fire at a hospital in Bharuch. Condolences to the bereaved families," Modi wrote on social media.

According to police, 18 people were killed in the blaze.

Local media quoted senior police officer in Bharuch, Rajendrasinh Chudasma, as saying that 16 COVID-19 patients and two staff nurses were killed in the fire.

Officials said there were around 50 other patients in the hospital at the time of the fire and they were shifted safely to other hospitals.

Police teams and firefighters rushed to the spot to douse the fire immediately after the incident.

Officials said it took close to two hours for the firefighters to douse the blaze.

Video footage showed remains of the patients on stretchers and in beds, besides heavy damage to the hospital wards.

The cause of the fire was not immediately known.

"An investigation has been ordered to ascertain the cause of the fire but preliminary reports suggest a short circuit could have triggered the fire," Saibel Sarkar, a disaster management official, said.

Gujarat Chief Minister Vijay Rupani directed two senior officers to rush to Bharuch for an inquiry, saying a judicial probe would also be initiated.

The chief minister has also announced a monetary relief of 5,398 U.S. dollars to each family that lost a member in the tragedy.

"I express my condolences to the patients, doctors and hospital staff who lost their lives in the fire accident at Bharuch hospital. The state government will provide assistance of 400,000 rupees to the families of each of the victims of the accident," he said.

Last week, 15 COVID-19 patients were killed in a similar fire in the Virar area of Palghar district in Maharashtra.

Chances of fire in Indian buildings are usually high as people often ignore safety standards vis-a-vis fire.

The fire at the COVID-19 ward of the hospital comes at a time when India is battling an unprecedented surge in daily infections and deaths, along with a shortage of oxygen and essential medicines in hospitals.

During the past 24 hours, the highest number of 401,993 new COVID-19 cases and 3,523 related deaths were registered across the country.