The space station will encounter pieces of the Kosmos 2251 military spy orbiter in the next few days, the Interfax news agency quoted a source at Russian Mission Control as saying.

"Two fragments of the Kosmos 2251 craft may pose a danger to the station," the unnamed source was quoted as saying.

The source added that the station may now have to manoeuvre out of the path of the approaching debris in a special operation tentatively planned for Thursday.

The Kosmos 2251 satellite was launched by Russia in 1993 and decommissioned just two years later.

The satellite crashed into a US Iridium-33 satellite in February 2009 in the first such space accident of its kind.

The collision created hundreds of smaller fragments that pose a danger to both the station