About 10,000 supporters of the opposition party yesterday blocked two bridges connecting this city and El Paso, Texas, to protest alleged fraud in elections won by the ruling party.

The action was prompted by a call from Gustavo Elizondo, the losing candidate for mayor of Juarez for the National Action Party, known as PAN.

The downtown scene became tense as antiriot police began lining up with riot shields and pushing supporters back off one bridge. The soldiers were then called back, but police stayed nearby as supporters chanted political slogans and began singing the Mexico anthem. No violence was reported.

In Durango earlier, about 1,000 PAN supporters took over city hall in another protest over the elections. The takeover, which occurred without violence, came at about 1 a.m., and the activists threatened to stay indefinitely, said government spokesman Jaime Lopez in Durango, 440 miles south of the U.S. border.

The moves came amid announcements of sweeping victories by the ruling PRI, including the mayor's seat in Juarez, in the July 6 elections held in six states. The only major victory for PAN, which is Mexico's largest opposition party, was in the mayor's race in the northern Baja California city of Ensenada, The Associated Press reported.