A woman rolls inside a giant plastic ball called Zorb in a park in the Bulgarian capital Sofia . The Zorb, invented by Australian David Akers, is a 3.5-metre diameter ball which relies on centrifugal force.

Bulgaria's Veselin Topalov, former world chess champion, takes part in a "blind" chess demonstration game against Italy's Alex Brunetti (background) in the Bulgarian capital Sofia.

Bulgarian men wave a red Soviet flag in front of the Monument of the Red Army in central Sofia. Several hundred Bulgarians gathered to celebrate the World War Two Victory Day.

Bulgarian Prime Minister Sergei Stanishev (C) walks with country's chief prosecutor Boris Velchev (L) after their meeting in Sofia. Bulgaria's Economy and Energy Minister Rumen Ovcharov was placed on forced vacation.

Bulgarian soldiers march during in a military parade in central Sofia. The event takes place each year to celebrate Saint George's Day, which is also Bulgarian Army Day. 

Elitsa Todorova (R) and Stoyan Yankoulov, Bulgaria's entries to the 2007 Eurovision song contest, perform the song "Water" during the first dress rehearsal of the semi-finals in Helsinki.

Students and teachers hold candles during a protest against the quality of Bulgaria's education system in central Sofia.