MAKHACHKALA, Russia — A journalist who wrote about alleged human-rights abuses was shot dead in Russia's violence-plagued North Caucasus province of Dagestan on Tuesday, law enforcement authorities and colleagues said.

Akhmednabi Akhmednabiyev, who had received death threats and survived an apparent assassination attempt in January, was killed by gunshots fired into his car by an unknown attacker near his home on the outskirts of Dagestan's capital, Makhachkala.

The killing underscored the risks faced by reporters who challenge the authorities in mostly Muslim Dagestan, which is plagued by corruption and an Islamist insurgency.

Akhmednabiyev was the 17th journalist to be killed or die in suspicious circumstances in Dagestan since 1993, according to the Caucasian Knot website he worked for as a correspondent for seven years. He also worked at the weekly Novoye Delo.

"This was clearly a targeted killing," said Grigory Shvedov, editor of the Moscow-based Caucasian Knot, adding that Akhmednabiyev was killed at the same spot where he survived an attack in January when three bullets missed him.

Colleagues and activists said Akhmednabiyev had reported on abductions and other abuses rights campaigners say security forces commit in the name of the fight against Islamist extremism.

"One gets the feeling that somebody is trying to stop even the thin trickle of truth about this aspect of life in Dagestan," the Russian human rights group Memorial said in a message to Caucasian Knot.

Shvedov said Akhmednabiyev had raised hackles by reporting on public calls for the resignation of a district chief in Dagestan and on the alleged persecution of Muslims deemed extremist by government officials and police.

In 2009, Akhmednabiyev's name was on a list of people including lawyers, journalists and activists that was distributed on leaflets In Makhachkala.

The leaflets said those listed would be targeted as revenge for the deaths of security forces and civilians, suggesting the anonymous authors suspected them of backing Islamist militants.

Another journalist on the list, Gadzhimurad Kamalov, founder of Chernovik, a newspaper that reported on police abuses and other human rights violations, was shot dead in December 2011.

Dagestan, which has become the focus of an Islamist insurgency rooted in two post-Soviet wars in neighbouring Chechnya, has been in an international spotlight following an April bomb attack at the Boston Marathon in the United States.

U.S. and Russian authorities are trying to determine whether bombing suspect Tamerlan Tsarnaev, who was killed by police after the Boston attack, had contacts with militants in Dagestan during a six-month visit to Russia last year.