A Feb. 24 indictment issued by Judge Eloy Velasco of Spain's anti-terrorism court specifically cites "Venezuelan governmental cooperation" with 12 members of the Basque separatist group ETA and guerrillas of the Marxist Revolutionary Armed Forces of Colombia (FARC).

The groups have been accused of training together to make sophisticated bombs and of plotting to assassinate Colombian President Alvaro Uribe with the support of Venezuelan officials.

ETA, whose acronym stands for Basque Homeland and Liberty, is considered responsible for the deaths of more than 800 people in its struggle for Basque independence from Spain, waged since the 1960s. FARC has similarly fought a half-century-old insurgency against the Colombian government.

Venezuela's leftist President Hugo Chavez has reacted angrily to the latest charges.

"I have nothing to explain to [Spanish Prime Minister Jose Luis Rodriguez] Zapatero or anyone else on this planet," he told reporters after the judge's indictment. He called the court findings "daring accusations without the slightest proof."

Mr. Chavez did not deny, however, that indicted ETA militant Arturo Cubillas Fontan has been on the Venezuelan government payroll. He said he would not be surprised if Spain was seeking his extradition and explained that Mr. Fontan had been given asylum in Venezuela by a previous government.

In statements released last weekend, the Venezuelan and Spanish governments said they had "surpassed difference," and vowed to cooperate against terrorism.

The statements followed calls from Spain's main opposition party to break relations with Venezuela. Earlier in the week, Spanish Foreign Minister Miguel Angel Moratinos had called Mr. Chavez to assure him that his socialist government had nothing to do with the indictment.

Mr. Chavez publicly called on Spain to keep a "closer eye on its court system."

Mr. Fontan has been employed as a deputy director for administration and services in Venezuela's Ministry for Land and Agriculture since 2005. His Venezuelan wife, Goizeder Odriozola, also works for the government as director of institutional relations in the Ministry of Popular Power.

Spanish authorities describe Mr. Fontan as a murder suspect who is "responsible for the ETA collective in this zone of Latin America since 1999, in charge of coordinating relations with FARC."

The 26-page indictment presented by Judge Velasco is based on intercepted electronic messages between FARC commanders, corroborated by police interrogations of FARC defectors and testimonies from captured members of ETA. The report also draws on past intelligence reports about contacts between ETA and FARC representatives in Cuba.

Venezuela is accused of providing protection for joint training programs arranged by Mr. Fontan. The report describes a 20-day course on weapons and explosives handling given at a jungle hide-out inside Venezuela, based on testimonies from FARC defectors who say they participated in the training at the time.

"The Caribbean bloc of FARC arrived by land accompanied by a person wearing [Venezuelan] Military Intelligence Directorate insignia and a Venezuelan military escort vehicle organized by Mr. Fontan," the Spanish court document states.

Mr. Fontan is not the first Venezuelan government official to be accused of belonging to a terrorist group. In 2008, the U.S. named Venezuelan diplomat Ghazi Nasr al-Din, who held top embassy posts in Lebanon and Syria, as a member of the Iranian-backed Islamic militant organization Hezbollah.

Another State Department report released in 2009 listed several Venezuelan security officials as "collaborators in FARC narco trafficking activities," including Ramon Rodriguez Chacin, who was interior minister.

The U.S. deputy assistant secretary of defense for the Western Hemisphere, Frank O. Mora, said last week that "we should not be surprised" about Spain's latest findings on Venezuela's link with FARC.

"This terrorist group does not only operate in Colombia but in other countries," he said. "Nonconventional but highly complex threats like guerrillas require multinational responses."

Mr. Chavez has repeatedly claimed that the accusations are part of a U.S. campaign to discredit him.

"Behind all this is the Yankee empire" he said last week in Uruguay, where he attended the inauguration of newly elected President Jose Mujica, who was himself a member of the Tupamaro guerrilla movement in the 1970s.

Spain's police investigations were first reported by The Washington Times two years ago, when chief prosecutor Javier Zaragoza traveled to Colombia to review computer records recovered from FARC leader Raul Reyes, who had been killed in a Colombian army raid on a rebel camp in neighboring Ecuador.

More than 100 e-mails exchanged between Mr. Reyes and other guerrilla commanders provided dates, locations and other details on joint operations with ETA. Mr. Chavez and his counterpart in Ecuador, President Rafael Correa, have claimed the intercepted computer records were U.S. "fabrications."

Purported e-mails from FARC commander Ruben Zamora, who is believed to operate along the Colombian-Venezuelan border, informed Reyes about arrangements with Mr. Fontan to incorporate four members of ETA into a FARC training camp.

Weapons technology reportedly exchanged between the groups involved the manufacture of cylindrical mortars for standoff attacks against defended installations, conversion of anti-tank rockets into anti-aircraft weapons, and the preparation of remotely controlled car bombs using cell phone-activated detonators and C-4 plastic explosive charges.

ETA teams were rotated through several guerrilla courses between 2003 and 2008. They included some of the Basque group's most dangerous fugitives, including Jose Maria Zaldua, who is wanted on multiple murder charges.

According to the Spanish indictment, e-mails between FARC leaders also mentioned the possibility of using ETA to mount assassinations against Colombian officials living in Spain, including former President Andres Pastrana and Colombian Ambassador Noemi Sanin.

"The friends from ETA would not have much difficulty locating these two," said a message from Reyes. FARC's current secretary-general, Alfonso Cano, suggested offering a cash reward.

Other details revealed by Spanish and Colombian authorities suggest Venezuela may have aided previous FARC attempts to gain international expertise for urban guerrilla operations. Colombian authorities have revealed immigration records showing that Irish Republican Army bomb experts arrested in Colombia in 2001 traveled between Venezuela and Colombia while they were training FARC.

Colombian defense officials have said that when the three IRA men escaped from their Colombian prison in 2005, they were smuggled across the border to a guerrilla camp in Venezuela.

There are also some unresolved cases involving Venezuelan-based Islamic militants.

Following the Sept. 11, 2001, attacks in the U.S., the FBI arrested a Venezuelan-born Arab, Hakim Mamad al-Diab Fattah, who attended flight school with the al Qaeda cell that crashed an airliner into the Pentagon.

He was deported to Venezuela where the FBI requested that he be interrogated and kept under surveillance. Although the FBI field office in Caracas informed the Venezuelan Interior Ministry of his travel itinerary and arrival time in Caracas, Venezuelan officials claimed al-Diab Fattah never re-entered the country.