This weekend’s local and regional elections in Mexico have been plagued by gang killings and candidate intimidation, highlighting the country’s escalating drugs war.
Voting will take place in more than a dozen states, including those on the US border.
Polls suggest the opposition Institutional Revolutionary Party will sweep the board.
A big win for the PRI would test support for President Felipe Calderon.
Candidates have campaigned vociferously despite the threat.
Polls show the economy is still voters’ top concern, as Mexico limps back from a deep recession. But drug-related violence and a weak justice system run a close second.
Last weekend, a politician who made the fight against drug violence his main electoral promise was shot dead while on campaign.
Rodolfo Torre Cantu was expected to win the vote in the north-eastern state of Tamaulipas.
21 people died in a gun battle between rival drug and people trafficking gangs 20 kilometres from the US border.
It is thought they were fighting for control of the supply route.