Once called Leningrad this old city has seen its share of bullets and betrayal over the years. Communism, converted to a market economy with a teeming corruption following tightly in the wake - a bad cocktail. Difficult terrain, even for a trained assassin.
Expect both guards and soldiers here to be well trained, experienced and highly suspicious of foreigners. Wide, open boulevards makes hiding difficult. Weapons aren't exactly scarce here, so law enforcement and criminals alike are well equipped. Proceed with caution.