A move to arrest a prominent opposition leader is aggravating tensions between Venezuela's government and opponents who accuse President Hugo Chavez of launching a new attack against his adversaries. Thousands of anti-government protesters filled an avenue Friday in the country's second-largest city, Maracaibo, after a prosecutor called for the arrest of Mayor Manuel Rosales, a prominent Chavez opponent who has been accused of corruption. Critics say Chavez and his legislative and judicial allies are leading a two-pronged offensive by persecuting opponents and increasing presidential power through a new measure putting all airports, highways and seaports under federal control. Several key ports were previously administered by Chavez opponents. "The persecution of the opposition is beginning, and I'm sure that Rosales won't be the last to go to jail," said Oscar Perez, an opposition leader.