'These kinds of murders have a chilling effect on freedom and respect of law within the society,' he said.

Russian President Dmitry Medvedev, however, quickly called for an investigation by state prosecutors and the interior ministry.

The incident comes less than a month after the murder of Natalya Estemirova, another human rights activist operating in Chechnya, an incident which provoked a harsh outcry internationally.

Sadulayeva and her husband headed the non-governmental organisation Let's Save the Generation. The charity helps young people in the troubled southern Russian republic, which was ravaged by war between separatists and Russian forces in the 1990s.