NIS, Serbia — In the command room there are large surveillance screens, in the warehouse rescue equipment; an unfinished gray concrete building serves as a training site. Is this a Russian-run disaster relief center in Serbia as Moscow claims, or is it an outpost for Kremlin spies in the heart of the Balkans?

Some Western NGOs and military analysts say the Russians have created a thinly disguised military base that is eavesdropping on American military interests in the Balkans. While Serbia is still close to Russia, its neighbors are increasingly distrustful of Moscow’s intentions and presence, especially ex-Soviet bloc states like Bulgaria, Romania and Hungary, which suffered under iron-fist communist rule for decades after World War II.

If it is a military operation, the base would be the Kremlin’s first in Europe outside the former Soviet Union since the collapse of the Warsaw Pact in the early 1990s.

The Western analysts say the base — jointly run by the Serbian and Russian governments and located near an airport in the southern Serbian town of Nis — is the Kremlin’s response to NATO’s expansion in the region. Every country around Serbia is either in the Western military alliance or wants to be.

The Russian partner in the center is its Ministry for Emergency Situations, a powerful semi-military outfit whose activities do include disaster relief, but it also carries out jobs for Russia’s security services. The ministry has long played a role in Serbia, including de-mining and clearing of unexploded ordnance from the 1999 NATO bombing of Serbia.

At the center’s opening ceremony in 2012, Sergei Shoigu — then Russia’s emergency minister, now its defense minister — said the longstanding speculation that Russia wants to create a military installation in Serbia is “a pure fabrication.”

NATO officials have refused to comment on the nature of the base, only saying they are not too worried about its role, whatever it is. EU officials have said that if Serbia becomes a member of the bloc, as it wants to, it will have to join the EU’s emergency relief programs and ditch the Russian ones.

During a recent visit to the so-called “Russian-Serbian Humanitarian Center” there was little visible evidence that the site was used for anything else but fighting floods, forest fires or other natural disasters. The images on the video screens in the command rooms shown to AP reporters were largely from surveillance cameras located throughout the installation. The warehouse contained an ambulance, a Russian-made Lada Niva jeep, packet tents, rubber boats and mostly firefighting equipment.

“Look at that James Bond technology,” joked the base’s Russian co-director, Viacheslav Vlasenko, as screens came rolling down for a video presentation of the center’s recent activities. Outside, Russian instructors were training Serbian firefighters.

Vlasenko said the center is far from equipped for spying on neighboring Romania, where U.S. anti-ballistic missile interceptors were recently installed, or Kosovo, where NATO peacekeeping troops and an American base are located.

“Those are only rumors,” Vlasenko said, adding: “It is not possible to change this center into a spy center. It is very small; we have a staff of only three Serbian citizens and five Russians and nothing more … and the building is not even ours.”

He complained that neighboring countries, such as NATO- and EU-member Croatia, or aspiring members Macedonia and Bosnia, have been reluctant to accept Russian help even during major natural or humanitarian disasters such as the recent refugee crisis, which last year saw nearly 1 million people cross the Balkans.

Vlasenko said the Croatians have, “without any explanation,” refused to let in giant Russian firefighting planes during recent major forest fires on the Adriatic coastline, and even rejected tents offered during the refugee crisis. Bosnia has not responded to an offer to sign an “agreement of understanding” that would spell out terms of joint action in case of natural disasters, he said.

“It’s only politics,” Vlasenko said. “They say Vladimir Putin is bad, Russia wants to dominate. … The political motivation should get out of humanitarian aid.”

Serbia — a traditional Russian Slavic ally — also wants to join the EU, but straddles the line between Russia and the West and has refused to participate in U.S.-EU sanctions against Moscow over Russia’s actions in Ukraine. Russia strongly opposes Serbia’s possible NATO membership.

The U.S.-led 1999 bombing of Serbia turned its people strongly against the West and toward Russia. The residents of Nis — which suffered heavy casualties during a cluster bomb strike — were divided when asked what they think of the Russian presence in their town.

“I would rather see our (Russian) brothers in our town than that Western scum,” said Radovan Mihajlovic.

Petar Jovanovic shared widespread local suspicion about the role of the base.

“There’s a lot of talk about (the Russian base) but the public does not know the whole truth,” he said. “I think there is something happening there which the public doesn’t know.”