With a sudden flash of light and a loud bang, a peaceful march calling for Ukrainian unity quickly erupted into exploding fireworks, chaos and fistfights on the streets of Donetsk in eastern Ukraine.
The demonstrators had only walked about half a mile down on of the city’s main boulevards before they were attacked by a mob of pro-Russian separatists.
We were at the very front of the march when the violence began.
A large group of masked men carrying clubs ran out of side streets and attempted to block the road ahead of us.
Fireworks and homemade bombs were thrown from the crowd and separatists answered back by throwing stones and beating people with their weapons.
Riot police who had been trailing along beside the marchers swiftly moved in, clashing with the attackers and trying to separate both sides.
We saw one member of the mob get hit in the head with an exploding homemade bomb and then a loud bang erupted at the feet of a police officer.
Marchers scattered in all directions with members of the pro-Russian mob chasing them down the street.
Several people were injured in the clashes.
One man, head gashed and bleeding, flashed us a simple peace sign as he walked off to find help.
In the midst of all the confusion we came upon an ambulance crew treating the wounded, where we met a Ukrainian journalist with a bloody bandage on his head who told us he was trying to flee when he was hit by a brick.
The demonstration had begun peacefully, with many of the marchers waving the sky blue and gold flags of Ukraine, singing patriotic songs and chanting slogans of unity.
Yet the confrontation was not entirely unexpected.
All through the day pro-Russian separatists were putting out the call on social media for their supporters to turn out and oppose the march.
Three weeks ago separatist gunmen occupied the main administration building in Donetsk and have since turned it into a heavily fortified command center in their bid to carve out an independent republic with strong ties to neighboring Russia.
Donetsk lies at the center of just one of Ukraine’s volatile breakaway eastern provinces and, as we witnessed today, it is simmering on the verge of all-out civil war.