LA PAZ - Bolivia on Saturday accused Spain of an abortive attempt to extract a wanted former government aide from Mexico's embassy in La Paz, prompting a sharp denial from Madrid.

It was the latest twist in a murky incident Friday involving embassy personnel in the Bolivian capital that has sparked a bitter diplomatic spat.

Several hours later, Bolivia's top diplomat accused Spanish embassy staff of trying to infiltrate the Mexican mission with a group of masked men in what it said was a violation of Bolivian sovereignty.

"We believe it was aimed at extracting the criminal Juan Ramon Quintana," said Interior Minister Arturo Murillo on Saturday, referring to a former aide to ousted Bolivian president Evo Morales who stands accused of sedition and terrorism.

"It failed."

The embassy in La Paz became the center of the diplomatic row after it sheltered nine or more officials from Morales's former government, some of them charged by the interim government in Bolivia with "sedition" or "terrorism" over the deaths of 36 people in violently quashed protests.

Both Spain and Mexico said the incident occurred on Friday when Spain's charge d'affaires Cristina Borreguero paid a brief visit to Mexican Ambassador Maria Teresa Mercado.

But Madrid issued a strongly worded denial.

"The ministry wishes to clarify that the charge d'affaires was purely making a courtesy visit and vehemently denies there was any aim to facilitate the exit of people holed up inside the building," a foreign ministry statement said.

Madrid said it would send a team of investigators to La Paz "in coming days." It would not confirm or deny reports an official had already left for Bolivia.

Murillo said he would ask interim Bolivian president Jeanine Anez and Foreign Minister Karen Longaric to order the expulsion of Spanish diplomats. "They cannot do whatever they want," he said. -AFP