A senior law enforcement official and six other people were killed on Wednesday when a car packed with explosive blew up on a road in Russia's volatile North Caucasus region in an attack, officials said may have been carried out by Chechen rebels.
Dzhabrail Kostoyev, the deputy interior minister in the province of Ingushetia, died when the powerful car bomb exploded at the moment his own car passed alongside outside Nazran, the main town in the province, where he was on his way to work, officials said. Two bodyguards and four bystanders were also reported killed.
Local officials and early Russian media reports said the attack had been carried out by a suicide bomber, but officials later backed away from that theory and said the explosion appeared to have been set off by remote control.
"In all probability, there was no one inside the car that exploded," Dmitry Guruliyov, the deputy prosecutor for Ingushetia, told AFP by telephone.
The explosion had a force equivalent to around 100 kilograms (220 pounds) of TNT, Guruliyov said.
Police said a manhunt was underway in Ingushetia to catch the perpetrators of the attack, but did not specify what leads they were pursuing.
There was no claim of responsibility but the blast bore the hallmarks of an attack by Chechen rebels and officials said they were taking seriously media reports that Chechen rebel warlord Shamil Basayev may have planned the assassination.
"We are working on that version," Interfax news agency quoted Ingushetia Interior Minister Beslan Khamkhoyev as saying in response to reports on Basayev's possible involvement.
An Internet website regularly used by Chechen rebels gave an account of a meeting earlier this week in one of Russia's provinces in the North Caucasus among several people it described as rebel commanders in the region and said Basayev also took part in the meeting.
"Shamil Basayev may have had a role in Wednesday's terrorist attack in Ingushetia," Echo Moscow said.
The Chechen rebel website, www.kavkazcenter.com, said the "commander" of the pro-Chechen rebels in Ingushetia, Yevloyev Magomed, was among those who participated in the meeting with Basayev. Magomed has been linked to other attacks on Russian officials in Ingushetia.
Khamkhoyev said investigators had determined that the attack was carried out by two associates of Basayev, whom he identified as Ali Taziyev, and Adam Nalgiyev, Itar-Tass news agency reported. He said both had taken part in a major raid led by Basayev in the province two years ago.
However another Russian news agency, RIA Novosti, quoted Ingushetia's prosecutor Makhmud Kalimatov as denying Khamkhoyev's assertion that the suspects had been identified. "No suspects have been identified. This is premature debate," Kalimatov said.
Attacks targeting Russian law enforcement officials are a frequent occurrence in Ingushetia, which borders Chechnya and where clashes between police and pro-Chechen fighters take place regularly.
In June 2004, several hundred rebels led by Basayev launched a large-scale assault on Russian government installations in Nazran, leaving dozens of people dead, most of them police officers, and seizing an arsenal of weapons.
Since then, there has been a steady stream of attacks against Russian officials and security forces in Ingushetia, Dagestan and other provinces in the North Caucasus near Chechnya.
Clashes between rebels and Russian forces in Chechnya itself continue to claim lives on a near-daily basis.
Russian forces are also regularly shown on state television in confrontations with "fighters" who usually number no more than two or three people holed up in an apartment building that is surrounded by special forces and blasted until the fighters are killed.