The Moscow Times reports:

A woman was killed Tuesday when an explosive she was carrying detonated in a minibus in Dagestan, reviving fears of a return of female suicide bombers after a three-year lull. The explosion, which injured eight people, ripped through a minibus with 15 people at around 11:20 a.m., just after the vehicle passed a police checkpoint at the village of Lenin-Aul, about 10 kilometers east of the Chechen border with Dagestan, said Mark Tolchinsky, a spokesman for the Dagestani Interior Ministry. "The woman was blown to pieces, eight passengers were wounded, three of them badly," he said by telephone from Makhachkala. The woman had not been identified as of late Tuesday. Tolchinsky said the explosion had likely been caused by a hand grenade, noting that investigators had found a linchpin at the site. It was unclear whether the woman had set off the explosion on purpose or even knew that she had been carrying an explosive. The minibus had been heading for the town of Khasavyurt.

Saidulah Batdalov, the lead investigator into the explosion, declined to comment when reached by telephone Tuesday. He told reporters from a local newspaper, Nastoyashcheye Vremya, that he doubted the woman was a suicide bomber, said Sergei Rasulov, the newspaper's deputy editor. "He told us that no specific elements of the so-called shahid belt used by Chechen suicide bombers, such as nuts and bolts that increase the force of the blast, were found in the minibus," Rasulov said. Nevertheless, most news reports about the blast Tuesday referred to the woman as a female suicide bomber.

Female suicide bombers appeared in Russia exactly five years ago, when women wearing explosives were among the 42 Chechen rebels who took 800 people hostage in Moscow's Dubrovka theater on Oct. 23, 2002. Chechen rebels denied any involvement in the minibus explosion in a statement posted on their Kavkaz Center web site Tuesday. Adam Dolnik, a terrorism researcher at the Centre for Transnational Crime Prevention in Australia, voiced doubt that the explosion was a premeditated suicide attack. He said a minibus filled with commuters was an "unlikely target" for rebels, who have in the past picked police and military targets for suicide attacks in order to make national headlines. In June 2003, a female suicide bomber attacked a commuter bus in North Ossetia, but the bus was carrying military personnel serving at an air base in Mozdok.

If Tuesday's blast was a suicide bombing, more attacks should be expected, said Dolnik, who recently published a paper about the Beslan hostage taking in September 2004, the last time female suicide bombers participated in an attack. Dolnik said Chechen rebel leader Doku Umarov had refrained from suicide bombings to avoid bad publicity as he tries to expand the insurgency across the North Caucasus. "If he is changing it now, then it is probably a sign of bad things to come," Dolnik said. Andrei Soldatov, a terrorism expert with the Agentura.ru investigative web portal, also said the explosion looked accidental, given a lull in news about the Arab fighters believed to be behind the hard-line tactics in the North Caucasus. "Even if the woman was a suicide bomber, she didn't seem to be prepared," he said. After the Beslan attack, special services have concentrated on hunting down the foreign insurgents who fought alongside the Chechen rebels, killing many of them. Female suicide bombers, called "black widows" by some journalists, have participated alone or as members of bigger terrorist squads in more than 20 attacks from 2002 to 2004 that claimed more than 700 lives.

If Tuesday's attack was by a suicide bomber, it might have been planned by some group other than Umarov's, said Louise Richardson, executive dean of the Radcliffe Institute for Advanced Studies and an author of several books on terrorism. "I expect the most likely explanation of the resumption is what is called 'the contagion effect' -- that is a tactic that is successfully used by one group is copied by other groups, even when they are very different," she said in a written response to questions.