One object landed in a garden while the smallest struck the roof of a house

Vietnamese military experts are probing three metal objects which are believed to have fallen from space near the country's northern border with China.

The the three objects were spread over a large area in the Tuyen Quang province according to local media reports.

The largest of the objects which weighed 45 kilograms, was found in a stream.

Members of the Vietnamese military have inspected the mysterious 'space balls' pictured, which fell to earth

The objects, which weighed up to 45kg are believed to be part of the fuel system of a satellite

Locals claimed they could hear 'thunder' in the minutes before the items were recovered.

One of the orbs, which weighed 6kg, narrowly missed a house, landing in the garden of a house in the Yen Bai region, while the smallest, weighing only 250 grams, landed on a roof before rolling onto the ground.

An initial investigation by Vietnamese defence officials determined the objects were of Russian origin, but could have been sold to a third country for use.

It is believed the objects are compressed-air tanks from some form of aircraft or rocket.

Officials said, as they have already landed, there is no need for public concern.

According to Thanhnien News, none of the devices were explosive.

Professor Nguyen Khoa Son of the State Space Science and Technology Program told Vietnam.net the objects could be part of a satellite fuel system.

He said the pieces could be the remains of a failed satellite launch or even parts of a decommissioned satellite which returned to earth.