MOSCOW (AP) — Four more people suspected of assaulting Russian police officers during a July opposition protest in Moscow have been arrested, Russia's top state investigative agency said Monday.

The Investigative Committee said the four were accused of pushing and grabbing officers at the July 27 rally. It added that another two people were being sought.

A series of summer protests rocked Moscow after Russian authorities refused to allow a dozen independent and opposition candidates to run for the city legislature in a Sept. 8 election. The demonstrations represented the largest show of discontent against Russian President Vladimir Putin's rule in seven years.

Police roughly dispersed some rallies that weren't sanctioned, detaining more than 2,400 people. Most were quickly released, but over a dozen were detained on charges of involvement in riots.

The authorities dropped charges against some of the protesters, but several people have been sentenced to prison terms of up to four years and a few others are in still custody or under house arrest awaiting court verdicts.

On Monday, the Moscow City Court rejected an appeal from one protester sentenced in September, Konstantin Kotov, and upheld a lower court's verdict that handed him a 4-year prison term. He was convicted on charges of repeatedly taking part in unsanctioned rallies.