MOSCOW (AP) — Russian authorities are ramping up their pressure on dissent ahead of the country’s parliamentary election, arresting one opposition activist and raiding several others’ homes. Andrei Pivovarov, the head of the Open Russia movement that dissolved itself last week, has been pulled off a plane at St. Petersburg’s airport and is to be taken to Krasnodar in southern Russia Tuesday as part of a criminal probe against him. Also on Tuesday, police raided a country home of opposition politician Dmitry Gudkov. The moves are part of a multi-pronged crackdown on the opposition that is seen as part of the authorities’ efforts to prevent any opposition groups from mounting a challenge to the main Kremlin-backed United Russia party in September’s election.