An explosion on a bus carrying workers in Chechnya today killed three people and wounded eight, security sources said.
The sources said the bus was carrying about 20 workers to Khankala, the main Russian military base just outside the Chechen capital of Grozny.
The attack in a region gripped by a decade of conflict came as dozens of heads of state began arriving in St Petersburg for celebrations, hosted by President Vladimir Putin, marking the 300th anniversary of Russia's second city.
