Belarus has deployed four new Russian anti-aircraft batteries on its border with Poland, a day after Warsaw received new F-16 fighter jets from the United States and amid Kremlin warnings of a new arms race in eastern Europe.
"Anticipating the arrival of the F-16s in Poland, Russia has sent to Belarus four S-300 anti-aircraft systems, which have already been put into service," a source in the air defence forces of the Commonwealth of Independent States (CIS), a loose grouping of 10 former Soviet republics, told Itar-Tass news agency.
Russia has also criticised US plans to build an arm of its missile defence system in eastern Europe, probably in Poland, saying Moscow would see it as an unfriendly move that would demand military and political measures in response.
Furthermore, the Kremlin is wary of US plans to deploy troops next year at bases in Romania and Bulgaria, and is rankled by the suggestion of Nato membership for Ukraine and Georgia, two former Soviet republics.
The first four of 48 new F-16s arrived at Poland's Krzesiny air base, near the western city of Poznan, on Thursday afternoon, where they were met by President Lech Kaczynski and blessed by the military's senior chaplain.
Poland bought the jets in a €3 billion deal to upgrade its air force to Nato standards, and to gradually replace Soviet-era MiG fighter planes.
A senior source at the CIS air defence headquarters played down the arrival of the state-of-the-art jets, however.
"The delivery of the F-16 fighter aircraft to the Polish armed forces will have no effect on the security of the air borders of the CIS," he insisted.
"The headquarters of the CIS anti-aircraft defence alliance keeps a close eye on actions by Nato aimed at widening [ its] possibilities in the Baltic states and in Poland."
But Poland's defence minister, Radek Sikorski, has questioned Moscow's motives for placing anti-aircraft missiles in Belarus, after his Russian counterpart Sergei Ivanov announced the move earlier this year.
"We respect Belarus's right to have anti-aircraft defences, but we are somewhat suspicious that they are right on our border, as my experts tell me it's not the best location militarily," Mr Sikorski said.
He added: "We find it strange that the announcement was made by the defence minister of a third party."
Russia has been riled by US talks with Poland and the Czech Republic about building a radar base and rocket silo in eastern Europe, which Washington says would protect the US and its European allies from missile attack from the Middle East, at a time when the Pentagon is fretting about Iran's suspected nuclear arms programme.
