Russia on Friday halted all flights by the Sukhoi-24 frontline bomber after the plane suffered two crashes in the space of a week, the military said.

On Wednesday a Su-24 crashed on landing in the northern Murmansk region, then on Friday another crashed in the southern Rostov region, Russian news agencies reported. In both cases the crews safely ejected.

"In connection with the fact that a second accident with a Su-24 plane took place within the space of a week, the military command has halted all flights," a military official told the Interfax news agency.

The Su-24 is a tactical attack plane dating back to Soviet times which does not typically carry nuclear weapons. It was heavily used in Russia's conflicts in Chechnya and Afghanistan.

The plane has been exported to Algeria, Libya, Iran and Syria, according to the website of its manufacturer, Sukhoi.

Accidents are common in Russia's armed forces, often caused by ageing military hardware.