Russian police detain a protester during a rally in Moscow on Sunday, May 6, the eve of Vladimir Putin's return as president. AFP/Getty Images
Thousands of Russians march in the country's capital during the latest anti-government demonstration. Putin was recently elected to a six-year term as president. AFP/Getty Images
Opposition supporters clash with riot police during the "March of Millions" protest on Sunday. AFP/Getty Images
As they marched, many protesters chanted slogans such as "Russia without Putin" and "Putin is a thief." AFP/Getty Images
Demonstrators agreed with Moscow authorities on a route to Bolotnaya Square, but a large number of them veered off the path. AFP/Getty Images
A young girl hoisted on someone's shoulders holds up a sign during the demonstration. AFP/Getty Images
Russian police officers attempt to block off a street during the rally in Moscow. AFP/Getty Images
More than 250 people were arrested, Moscow police said. AFP/Getty Images
Demonstrators carry a giant white ribbon as they march on Sunday. In Russia, the white ribbon has emerged as a symbol of the opposition movement. AFP/Getty Images
After the arrests, authorities slowly moved everyone out of the area. AFP/Getty Images
Leftist radical group leader Sergei Udaltsov, center, attends Sunday's rally. He was among the people arrested. AFP/Getty Images
Many protesters expressed disappointment that the event was not peaceful. AFP/Getty Images
Leading opposition figure Boris Nemtsov, center, was also among the demonstrators who were arrested. AFP/Getty Images
A protester wears a Guy Fawkes mask Sunday. AFP/Getty Images