BESLAN, Russia — Thousands are gathering in the southern Russian town of Beslan to mourn the hundreds of people who died five years ago in Russia's worst terrorist attack.

Mourners on Tuesday are filling the gymnasium of Beslan's school No. 1, where more than 1,000 hostages were held for nearly three days without food or water by 32 heavily armed militants.

The ordeal ended on Sept. 3, 2004, in a botched rescue attempt that resulted in the deaths of 334 people, more than half of them children, in the North Caucasus town.

In the attack's aftermath, the Kremlin made sweeping changes to the country's electoral system, tightening its grip on power.

A recent upsurge in violence across Russia's North Caucausus has undermined the Kremlin's claims it is bringing stablility to the region.