DUSHANBE, October 21, 2015, Asia-Plus -- President Vladimir Putin said on October 20 Russia had foiled 20 militant attacks this year and was stepping up efforts to root out domestic terrorism, almost three weeks after launching air strikes against Islamist fighters in Syria.

The Russian authorities have arrested a number of suspected militants since the Syria campaign started on September 30, a development that stoked fears that militants could seek revenge by attacking targets inside Russia.

A week ago, Russia''s FSB Federal Security Service said it had foiled a plot to attack Moscow''s busy underground using explosives, news that rekindled painful memories among Russians of a series of deadly attacks on the metro in the 2000s.

Some of the men arrested in connection with the plot had undergone Islamic State training in Syria, the FSB said.

Reuters reports that speaking at a meeting in the Kremlin with military officers, Putin said the FSB had killed 112 militants and arrested more than 560 so far this year.

“The complex international situation demands that we strengthen our counter-terrorism work including inside our own country,” said Putin.

“We need to act just as energetically and efficiently (as in the past). It is vital to expose the links between Russian militants with international terrorist groups and their sponsors.”

Putin said Islamic State militants in Syria were planning to destabilize other regions and were recruiting Russians and citizens of other former Soviet states with a view to expanding their operations.

Russia''s main breeding ground for Islamist militants is in the mainly Muslim North Caucasus region, including in the internal republics of Chechnya, Dagestan and Ingushetia, where Islamist insurgencies have been simmering for years, according to Reuters .

Russia says it is also worried about the possible spread of jihadism to the former Soviet republics of Central Asia.