Pittsburgh, Sep 26 (RIA Novosti) At least 70 protesters were detained on the first day of the G20 summit here in Pennsylvania Friday, police said.

Those arrested were fined for public order offences and later released, a police spokesman said.

Earlier in the day, protesters clashed with police, throwing rocks and garbage bins at officers, who retaliated with tear gas.

The Pittsburgh G-20 Resistance Project said six protest marches would be held during the two-day summit.