Russia ? A popular opposition figure in Russia’s restive Ingushetia province was gunned down Sunday morning in the latest killing of a government critic in the North Caucasus, prompting outrage from human rights groups and raising fears of further violence in the region.

Maksharip Aushev, a businessman who had led mass protests against alleged abuses by the government’s security forces, was driving on a major highway in the neighboring province of Kabardino-Balkaria when a passing vehicle sprayed his car with more than 60 bullets, authorities said. The attack also seriously wounded a passenger.

Colleagues condemned the slaying as an attempt to silence voices critical of the authorities, and said it sent an especially chilling message because Aushev held a post on a human rights council established by Moscow and enjoyed the support of Yunus-Bek Yevkurov, the local governor appointed by President Dmitry Medvedev last year.

Yevkurov has reached out to human rights activists and the opposition, offering them a degree of protection, but Aushev’s killing suggests that he, and by extension the Kremlin, may be losing control over the overlapping law enforcement agencies fighting a growing Islamist insurgency in the region.

Aushev had accused the security forces of conducting an indiscriminate campaign of abductions, torture and killings in Ingushetia that had only strengthened the rebels.