Tear gas as anti-Obama protesters clash with Greek police

ATHENS, Greece (AP) — Greek riot police used tear gas and stun grenades Tuesday in Athens to disperse about 3,000 left-wing marchers protesting a visit by President Barack Obama after they tried to enter an area off-limits to demonstrators.

The violence broke out as youths in motorcycle helmets and gas masks, armed with wooden clubs and petrol bombs, tried to break a police cordon in front of a barrier formed by police buses.

Rioters pulled back to the Athens Polytechnic university complex, site of a 1973 student uprising, and engaged in running street fights with police, throwing dozens of petrol bombs.