Venezuelan President Hugo Chavez said on Sunday that his security forces are investigating opponents for planning violence to disrupt next month's recall referendum on his rule.

Chavez accused his opponents of rejecting calls for negotiations before the Aug. 15 referendum in the world's fifth largest oil exporter.

"We have begun to conduct raids, to decommission weapons and explosives, we are conducting intelligence operations," the president said in his weekly broadcast. "The opposition is refusing to negotiate, they are refusing to accept reality."

An international mission led by the Organization of American States and former US President Jimmy Carter last year brokered an accord to recognize the referendum as a way to end more than two years of violent confrontation.

Chavez, who won the 1998 elections, has survived a brief coup in 2002 and months of street protests by opponents.

Opposition leaders said they will not negotiate with the government until they are guaranteed a fair vote. They want international observers to guarantee a clean recall referendum against a president.

A diverse coalition and the opposition signed an accord on Sunday on their proposals for a new government, including constitutional reforms to reduce presidential power.

The pact calls for primary elections, probably on Aug. 22, to decide on an opposition candidate for elections after the recall. Elections for a new president must be called 30 days after the referendum if Chavez loses.