Thousands of Russians took to the streets in Moscow Monday amid suspicions of polling irregularities by the ruling United Russia Party.

Russian police say roughly five-thousand people marched toward the Kremlin Palace shouting slogans against Prime Minister Vladimir Putin. Some 300 demonstrators were arrested during the rally.

It is the largest antigovernment protest to be held in the Russian capital in recent years.

It is tentatively estimated that the United Russia Party won 238 out of 450 parliamentary seats in the general elections held on Sunday.