Mexican electoral officials have begun a partial recount of ballots from last month's disputed presidential election.

Soldiers were on guard Wednesday as judges and representatives from political parties began recounting the votes from nine percent of the 130,000 polling stations.

As the recount started, supporters of presidential candidate Andres Manuel Lopez Obrador blocked access to three foreign banks to protest what they say was fraud in the election.

On Tuesday, many of the candidate's supporters seized toll booths in Mexico City, letting commuters drive through without paying.

Lopez Obrador and his supporters are demanding a full recount of the votes. Lopez Obrador lost the election to conservative rival Felipe Calderon by about six tenths of one percent.

The electoral court has until September 6 to officially declare a president-elect. Incumbent President Vicente Fox leaves office December 1.