Updated at 11:28 a.m. Eastern

MOSCOW The U.S. Ambassador to Russia was summoned Wednesday by the Russian foreign ministry in connection with an alleged spy detention in Moscow.

Michael McFaul entered the ministry’s building in central Moscow and left half an hour later without saying a word to journalists waiting outside the compound.

Russia’s Federal Security Service said Tuesday that it briefly detained Ryan Fogle, a third secretary at the U.S. Embassy in Moscow, who was carrying special technical equipment, disguises, written instructions and a large sum of money. Fogle was later handed over to U.S. Embassy officials.

The FSB, which is the successor to the Soviet-era KGB, said Fogle was trying to recruit a Russian counterterrorism officer who specializes in the Caucasus, a region in southern Russia that includes Chechnya and Dagestan. The suspects in the Boston Marathon bombings are ethnic Chechen brothers and the elder brother spent six months last year in Dagestan, 바카라 프로그램 now the center of an Islamic insurgency.

U.S. investigators have been working with the Russians to try to determine whether Tamerlan Tsarnaev had established any contacts with the militants operating in Dagestan.

The detention of Fogle appeared to be the first case of an American diplomat publicly accused of spying in about a decade and seemed certain to put further strain on relations between the two countries.

In another twist to the story, Russian state television aired video Wednesday provided by Russia’s security services claiming that another alleged American spy was expelled earlier in 2013. In the clip, a man identified only as an FSB operative and sitting in near darkness said a “CIA operative” was expelled in January. He said the FSB then asked its U.S. counterparts to halt this “disturbing activity.”