Tehran, Iran (CNN) -- Saturday began with calm on the streets of Tehran but witnesses said scattered clashes erupted later in the evening between Iran's security forces and demonstrators gathering at key sites to mark the first anniversary of a contested presidential election.
The first skirmishes Saturday were reported at about 6 p.m. as uniformed riot police and plain-clothes security forces, many on motorcycles, chased away growing crowds along the sidewalks of Tehran's Vali Asr Square, witnesses said.
Witnesses told CNN they saw several people struck by batons as they were running away. They said at least five people were arrested, blindfolded, handcuffed and swept away by security officers, who also used tear gas to disperse the crowds.
Due to government restrictions on the international media, CNN is unable to independently verify the information from the Iranian witnesses.
