President Hugo Chavez lashed out at Spain's prime minister Wednesday for asking Venezuela to respond to a Spanish judge's accusation that his government collaborated with Basque separatists and Colombian rebels.

Spanish Prime Minister Jose Luis Rodriguez Zapatero on Monday demanded an explanation from Venezuela after Judge Eloy Velasco announced that an investigation turned up evidence Chavez's government facilitated collaboration between the Basque group ETA and Colombia's leftist rebels — and the two groups planned to assassinate Colombia's president.

The following day, Spain's foreign minister said that he had spoken with Chavez and Venezuela's foreign minister and that both denied the allegations but promised an investigation.

But on Wednesday Chavez warned that diplomatic relations between the two countries could be hurt if Spanish officials insist on seeking answers from Venezuela.

"We don't have anything to explain," Chavez said during a televised speech. "Relations will depend on the Spanish government's attitude."

Chavez denied his socialist government maintains ties with ETA or the Revolutionary Armed Forces of Colombia, which are classified as terrorist organizations by the European Union and the United States.

"This is a government that does not, and will not, support terrorist groups," Chavez said.

ETA has been waging a violent campaign since the late 1960s to create an independent Basque homeland in northern Spain and southwestern France. The FARC has been battling since 1964 to topple successive Colombian governments and establish a Marxist-style state.

Velasco indicted six members of ETA, most of them exiled in Latin America, and seven members of the FARC for a variety of alleged crimes, including plotting to kill former Colombian President Andres Pastrana and Colombia's current president, Alvaro Uribe.

Velasco said the investigation that began in 2008 turned up evidence of "Venezuelan governmental cooperation" in the collaboration between the two groups. ETA members have received training or taught in FARC rebel camps, and FARC members traveled to Spain to try to kill Pastrana and Uribe, with help from ETA, Velasco wrote.

Velasco identified suspected ETA member Arturo Cubillas Fontan as a key figure in links between ETA and the FARC. The man lives in Venezuela, has held a job in the Chavez government and may still have one, the judge wrote.

The probe is based largely on e-mails that were in a computer used by a FARC leader named Raul Reyes, who died in a Colombian military raid on a FARC camp in Ecuador in March 2008.

Chavez noted one of his predecessors as president, Carlos Andres Perez, and former Spanish Prime Minister Felipe Gonzalez signed agreements in 1989 allowing several Basque separatists to take up residence in Venezuela after peace talks between Spain's government and ETA representatives broke down.

"These people came here and they became Venezuelans," Chavez said.

Chavez did not address the judge's allegation that Cubillas Fontan has worked for his administration.

Spanish Attorney Daniel Portero, who closely follows ETA's activities, told The Associated Press that he expects Spain's judiciary to run into difficult obstacles as it attempts to bring exiled members of the Basque separatist group to justice.

"It's very complicated," Portero said, noting Spain's government doesn't want to spoil warm relations with Venezuela'.

Portero leads a nonprofit organization, Dignity and Justice, that has been involved in roughly 50 criminal cases against ETA members. The lawyer's father, a Spanish prosecutor, was killed by ETA in 2000.