Huge explosions rocked a munitions depot in the Republic of Congo's capital Brazzaville Sunday, killing at least 100 people and leaving hundreds of others injured, the government said.

A European diplomat said earlier that at least 150 bodies had piled up in military hospitals in the city and that more than 1,500 people had been injured in the blasts.

"There are more than 100 dead," Interior Minister Raymond Mboulou told AFP by telephone, citing civilian and military hospitals. "The injured are difficult to enumerate for the moment."

Mboulou said the area around the munitions depot had been devastated with "many houses burned to the ground".

Government spokesman Bienvenu Okiemy said on state television: "There are more than 100 deaths and several hundred wounded."

The interior minister meanwhile said President Denis Sassou Nguesso had taken charge of relief operations.

Sassou Nguesso announced an investigation into the tragedy. Speaking on state television, he said: "We will help everybody, especially the wounded. We will ask chemists and doctors to tend to them."

A number of wounded, many wearing military uniforms, were seen receiving first aid in the streets, an AFP correspondent said.

A series of explosions rocked the Mpila military barracks in the east of the capital early Sunday after a blaze in two munitions depots.

The force of the explosions blew out windows across the Congo River in Kinshasa, the capital of neighbouring Democratic Republic of Congo, from where a huge pall of smoke could be seen hanging over Brazzaville.

At least five strong explosions were heard between 8:00 am (0700 GMT) and 10:45 am (0945 GMT).

There were also other weaker detonations which continued into the late morning, hampering firefighters and rescue workers.

"We count at least 150 dead in the military hospitals and around 1,500 injured, some of them seriously," the European diplomat said when contacted by telephone from Paris.

"I experienced the apocalypse," said Jeanette Nuongui, the sole survivor from a family home that was destroyed in one of the explosions.

"It is by the grace of God I am here. My mother died, my father, my two brothers and my two sisters also. There's nothing left," she added.

AFP correspondents in Brazzaville had earlier reported seeing four bodies, including that of a young girl, in a clinic near the barracks, while the Chinese Xinhua news agency said six Chinese workers were killed, one was missing and dozens injured in the blasts.

They were all employees of the Beijing Construction Engineering Group and about 140 Chinese workers were at a construction site when the blasts went off, Xinhua added.

There was no official word from the government on the cause of the explosions.

A number of houses were completely destroyed, while others had windows and doors blown out and roofs lifted, an AFP correspondent said.

A Catholic church, close to the barracks, was also damaged when the explosions occurred during Sunday mass.

"It's a munitions depot that caught fire in Mpila. That's next to the presidential palace. I saw two people injured. One had a leg injury, the other a wound to the shoulder," a woman living in Brazzaville told AFP.

"They had probably been hurt by falling debris from houses. A wall fell down in my home," she added.

"There are many people on the street. They are running away, barefoot, carrying parcels on their heads. Some are hardly dressed. There are no cars, no buses, no taxis," she added.

River traffic between Kinshasa and Brazzaville was also suspended, a Kinshasa port official said.

The dormitory building of China's Huawei technology giant was badly damaged, but there were no casualties reported there, Chinese officials said.

French Foreign Minister Alain Juppe said he had ordered his office to send emergency aid "which will arrive soon in Brazzaville."