KIEV, Ukraine — Fearing that a call for a truce was a ruse, protesters tossed firebombs and advanced upon police lines today in Ukraine’s embattled capital. Government snipers shot back and the almost-medieval melee that ensued left at least 33 people dead.

Video footage on Ukrainian television showed shocking scenes of protesters being cut down by gunfire, lying on the pavement as comrades rushed to their aid. Trying to protect themselves with shields, teams of protesters carried bodies away on sheets of plastic or on planks of wood.

Protesters were also seen leading policemen with hands held high around the sprawling protest camp in central Kiev Ukraine’s Interior ministry says 67 police were captured in all. They are being held in Kiev’s occupied city hall, an opposition lawmaker said.