MOSCOW — A powerful explosion tore into a minibus in Russia's tumultuous Caucasus region on Thursday, killing at least eight people in what investigators said might have been an act of terrorism, possibly by a female suicide bomber.
Investigators and local officials said at least 30 people were wounded in the blast, which occurred close to the central market in Vladikavkaz, the capital of North Ossetia, a Russian region that borders South Ossetia, the separatist enclave where Russia and Georgia fought a short, bloody war in August.
The investigative committee of the prosecutor's office in Moscow said it had opened a criminal inquiry into whether the bombing was a terrorist attack, a statement on the committee's Web site said, though no information on possible suspects was released.
"One of the theories is that this could have been a female suicide bomber," said Larisa B. Khabitsova, the chairwoman of North Ossetia's Parliament.
While she cautioned that it was too early to draw definitive conclusions, she added, "It is absolutely clear that this was a terrorist attack."
A spokesman for the investigative committee said at a news conference in Moscow that investigators had found bomb fragments at the site of the blast.
Russian television showed the scorched minibus, its right-side sliding door blown off and windshield shattered, and pools of blood in the street.
"According to preliminary data, the explosion most likely occurred not inside the minibus, but at the bus stop," said Alla Akhpolova, a spokeswoman for the local police.
Several of the wounded are in serious condition, Akhpolova said.
North Ossetia, which also shares borders with Chechnya and Ingushetia, two violence-plagued Russian republics, has been the site of major attacks in the past. In 2004, a raid by Chechen rebel fighters on a school in Beslan, not far from Vladikavkaz, resulted in the deaths of more than 300 people, many of them children.
Last month, the deputy mayor of Vladikavkaz was wounded when a bomb exploded in his car. "We resolutely condemn this brutal murder of innocent people and express our sincere condolences to the victims' families," said John Byerly, the U.S. ambassador to Russia, in comments reported by Interfax -->.