Estonia angry at Russia 'abduction' on border
Estonia's foreign ministry has summoned the Russian ambassador over what it calls the abduction of an Estonian security official by "unidentified individuals from Russia" on the border.
A ministry statement said the incident had taken place inside Estonia on Friday, near Luhamaa border checkpoint.
The missing Estonian official works for the Estonian Internal Security Service.
Russia says it detained an Estonian security official on a "spying operation" on Russian territory.
The head of Estonia's security police said it was ruling out any "political motive" for now.
However, the foreign ministry in Tallinn called it "a very disturbing incident". It comes amid heightened tension with Russia.
"We expect to receive all manner of help and co-operation necessary from Russia in solving this case and bringing the Estonian citizen back to Estonia," said the Baltic state's Foreign Minister, Urmas Paet.
'Signs of a struggle'
The incident came on the second day of a key Nato strategy summit in Wales. Extra Nato military support for European countries bordering Russia was high on the agenda.
US President Barack Obama visited Estonia on Wednesday to discuss security issues.
According to Estonian security police (Kapo) chief Arnold Sinisalu, signs of a struggle had been detected at the scene. "Tracks leading from Russia to Estonia are evident," he said. "[They show] a scuffle occurred, then they lead back."
"We have no indications that a shooting occurred," he added. "There is no blood at the scene."
The FSB in Moscow told Russian news agencies that a Kapo official named Eston Kohver had been detained on Russian territory and was now being investigated.
He was, the FSB said, carrying a pistol, 5,000 euros (£3,980; $6,539) in cash, an eavesdropping device and "other materials related to intelligence-gathering".
The Estonian daily Postimees said the missing Kapo official had been involved in tackling cross-border crime.
The kidnappers jammed Estonian radio communications and used a smoke grenade during the incident, reports say.
Estonian President Toomas Hendrik Ilves tweeted "let's not jump to conclusions, folks. Estonia extremely good at stopping organised crime & smuggling. Among best controlled borders in EU".