MOSCOW (AFP) - Russia on Friday (Aug 19) said it was investigating after the Islamic State in Iraq and Syria (ISIS) group claimed responsibility for an axe attack that injured two at a police checkpoint outside Moscow.

Two men armed with firearms and axes on Wednesday attacked a traffic police checkpoint on a highway 20km east of Moscow, injuring two officers, before being shot dead by police.

The attack, which investigators initially attributed to a conflict with the police, was then claimed by the radical group on Thursday in a video on the ISIS-linked website Amaq.

In the video, two young men identified as the attackers say they have joined the jihad and are under the command of ISIS leader Abu Bakr al-Baghdadi.

"We are in Moscow on orders of our emir... this is payback for your killing of our brothers every day in Syria," one of the men says in Russian.

SITE Intelligence Group said Amaq identified the two attackers as ISIS fighters and named them as Uthman Mardalov and Salim Israilov.

The two attackers were active on terrorist websites and came from the mainly Muslim North Caucasus republic of Chechnya, a source in Russian security forces told Interfax news agency on Friday.

A separate security source confirmed to the RIA Novosti state news agency that the attackers resembled the men in the video, while adding that the investigation was considering various motives.

Russia has been conducting air strikes in Syria since September 2015, with its campaign bolstering the regime of Bashar al-Assad at a crucial time in the protracted multi-front war in the country.

Though there have been few reports of IS actions inside Russia since then, an ISIS-linked group has claimed taking down a Russian jet flying from Egypt in October, which crashed in the Sinai peninsula killing all 224 people on board.