A massive explosion at a government-owned steel plant in the southern Indian state of Andhra Pradesh has killed at least 11 people, police say.

印度警方称，南部安得拉邦的一座国有钢铁厂发生大爆炸，造成至少11人死亡。

The blast on Wednesday night triggered a fire in the plant in the coastal¹ city of Visakhapatnam. At least 16 other workers suffered serious burn injuries.

The blast took place when workers were checking a newly-installed oxygen unit in the plant, reports said.

The death toll² is expected to rise as some of the injured are critical.

"We found people with 75% burns who were rushed to the hospital," news agency AFP quoted a spokesman for the plant as saying.

Reports said about two dozen workers and top officials were present at the plant at the time of the accident.

The Hindu newspaper reported that at least three senior officials were among those killed.

Witnesses said the explosion was so powerful that cars parked outside the unit were flung in the air.

The 41-year-old Rashtriya Ispat Nigam Limited (RINL) plant, located 600km (370 miles) from the state capital, Hyderabad, is one of India's biggest steel producers.

The plant has expanded over the past four years and added new units.