Suicide bomber kills 16 in busy Russian market
A suicide bomber has killed at least 16 people and wounded 100 others at a market in Vladikavkaz in southern Russia, officials say.
Bodies lay strewn and buildings were damaged by the explosion, which went off in a car packed with metal bars, bolts and ball bearings.
People rushed to help the wounded, many of whom are in a critical condition.
President Medvedev vowed to track down the "beasts" who carried out the bombing.
The square in front of the market was stained with blood and littered with damaged cars.Schools evacuated
The Russian emergencies ministry has sent a plane loaded with medics and equipment to treat and evacuate the injured.
This is the latest in a spate of very serious attacks in recent weeks.
At the weekend there was a suicide car bombing in Dagestan, killing a number of soldiers.
Experts say the leadership of various Islamist militant groups in the North Caucasus is currently divided and those vying to control the movement are trying to prove who is the most powerful.
The Russian military is also fighting back, and there are a large number of troops in the region.
But with the insurgency escalating, and spreading, it's clear that Russian military forces are not in control.
The area around the market was busy at the time, partly because there is an employment office nearby.
Reports said schools and kindergartens were evacuated throughout the city in response to an anonymous bomb threat.
Russia's North Caucasus region has been beset by Islamist and separatist violence and the area around the market in Vladikavkaz has been targeted before.
In the deadliest attack, 55 people were killed in an explosion in 1999.
Vladikavkaz is the capital of the Russian republic of North Ossetia, next to the volatile region of Ingushetia.
It also borders on South Ossetia, a tense breakaway region of Georgia where Russia and Georgia went to war two years ago.
Prime Minister Vladimir Putin told a meeting of Russian Muslim leaders that "the people who do this, are people without a soul, without a heart."
This is the latest in a spate of very serious attacks in the North Caucasus in recent weeks.
Experts believe rival militant groups may be vying for supremacy in the region, our correspondent says.Spasms of violence
North Ossetia has escaped the worst of the violence that has wracked neighbouring republics and is predominantly Christian.
Mr Putin said that the bombing was intended to cause hostility between different ethnic groups. "We mustn't allow this," he said.
Shootings and bomb attacks have become increasingly common in Dagestan and Ingushetia, spilling over from Chechnya, where the authorities have clamped down on militant groups.
Nevertheless, North Ossetia has seen severe spasms of bloodshed.
It was the scene of the Beslan school atrocity in 2004, where militants took hundreds of children hostage. In the bloodbath that ensued, more than 330 people were killed.