Hundreds of armed insurgents attacked a border guards' camp in Luhansk, eastern Ukraine. At least five rebels were killed in the clash, a spokesman for the guards said.
Pro-Russian insurgents, who have seized government and police buildings across eastern Ukraine, have waged increasingly aggressive attacks on government-held checkpoints and garrisons in an attempt to seize weapons and ammunition from Ukrainian forces.
The initial attack by about 100 insurgents was met by firing from the border guards, and the number of attackers swelled to around 400 a few hours later.
One insurgent fighter in uniform, who gave his name as Vlad Sevastopolsky, told AP pro-Russian militants surrounded the base but offered Ukrainian troops a safe corridor out, as long as they surrendered their weapons.