The US National Security Agency has spied on more than 60 million phone calls in Spain in one month alone, according to a document published by a Spanish newspaper.
The report in El Mundo newspaper came a week after Le Monde reported similar allegations of US spying in France, and German magazine Der Spiegel reported that a document shows that the NSA tapped Chancellor Angela Merkel's mobile phone.
El Mundo said that a document provided by Edward Snowden, the former NSA contractor, shows that the NSA monitored the phone calls from December 10, 2012, until January 8, 2013, but not their content.
The news broke hours before Spanish Foreign Ministry officials were to meet the US ambassador to Spain, James Costos, who has been summoned to provide information about alleged US spying on Spanish telecommunications.
Meanwhile, a German newspaper has reported that US President Barack Obama knew his intelligence service was eavesdropping on Angela Merkel as long ago as 2010, contradicting reports that he had told the German chancellor he did not know.
Germany received information this week that the NSA had bugged Merkel's mobile phone, prompting the German government to summon the US ambassador.
The NSA denied that Obama had been informed about the operation by the NSA chief in 2010, as reported by the German paper Bild am Sonntag on Sunday.
But the agency did not comment directly on whether Obama knew about the bugging of Merkel's phone.
Both the White House and the German government declined comment.
The Wall Street Journal reported on Sunday that the NSA ended the programme that involved Merkel after the operation was uncovered in an Obama administration review that began this summer.
The programme also involved as many as 35 other world leaders, some of whom were still being monitored, according to the report, which was attributed to US officials.
Caitlin Hayden, US National Security Council spokeswoman, said in a statement that Obama had ordered a review of US surveillance capabilities.
Citing a source in Merkel's office, some German media have reported that Obama apologised to Merkel when she called him on Wednesday, and told her that he would have stopped the bugging happening had he known about it.
But Bild am Sonntag, citing a "US intelligence worker involved in the NSA operation against Merkel", said General Keith Alexander, NSA chief, informed Obama in person about it in 2010.
"Obama didn't stop the operation back then but let it continue," the newspaper quoted the source as saying.
'Reports not true'
The NSA said, however, that Alexander had never discussed any intelligence operations involving Merkel with Obama.
"[General] Alexander did not discuss with President Obama in 2010 an alleged foreign intelligence operation involving German Chancellor Merkel, nor has he ever discussed alleged operations involving Chancellor Merkel", Vanee Vines, NSA spokeswoman, said in an emailed statement.
"News reports claiming otherwise are not true."
The Frankfurter Allgemeine Sonntagszeitung, another German paper, reported on Saturday that Obama had told Merkel during their call that he had been unaware of any spying against her. It did not cite its sources.
But Bild am Sonntag said Obama in fact wanted more material on Merkel, and ordered the NSA to compile a "comprehensive dossier" on her.
Obama, according to the NSA man, did not trust Merkel and wanted to know everything about the German," the paper said.
White House spokeswoman declined to comment and reiterated the standard policy line that the US gathers foreign intelligence of the type gathered by all nations.