An obscure far-left Greek group has claimed responsibility for a hand grenade attack that lightly injured a police guard outside the French embassy in Athens.

In a posting on a left-wing website, the Organization for Revolutionary Self-Defense says last Thursday's attack was prompted by France's participation in the "thieving capitalist war against the planet."

Monday's posting also deplored France's migration policy, riot control measures and imprisonment of a Lebanese extremist. The group said it had also fired a couple of rounds at the Mexican embassy building in Athens in August, which lodged harmlessly in the building facade. The lengthy proclamation criticized the Mexican government.

Last week's attack was carried out in one of the Greek capital's most heavily guarded areas, just across the road from Parliament.