MOSCOW – The suicide bomber who killed 35 people at Moscow’s busiest airport was deliberately targeting foreigners, investigators said Saturday, which would mark an ominous new tactic by separatist militants in southern Russia if he was recruited by an Islamist terror cell.

Federal investigators know the identity of the bomber, a 20-year-old native of the volatile Caucausus region, where Islamist insurgents have been battling for years for a breakaway state.

But the country’s top investigative body stopped short of naming him, fearing it would compromise ongoing attempts to identify and arrest the masterminds of the Domodedovo Airport attack on Jan. 24. The blast also wounded 180 people.

There has been no claim of responsibility, but security analysts suspect Islamist separatists of organizing the bombing, because of its magnitude and method.

“It was no accident that the terrorist act was carried out in the international arrivals hall,” federal investigators said in a statement. “The terrorist act was aimed first and foremost at foreign citizens.”

The victims were mainly Russians, but also included one person each from Britain, Germany, Austria, Ukraine, Tajikistan, Kyrgyzstan and Uzbekistan.

The violence stemming from the predominantly Muslim Caucasus region originates from two bloody separatist wars in Chechnya in the past 15 years. Federal forces wiped out the large-scale resistance, driving the insurgency into the mountains and into neighboring provinces. The rebels seek an independent Caucasus emirate that adheres to Shariah law.

Caucasus rebels have claimed responsibility for a number of deadly attacks over the years, including a double suicide bombing on the Moscow subway system in March 2010 that killed 40 people. One of the subway stations hit was under the Federal Security Service headquarters in downtown Moscow. The service is the main successor to the feared Soviet KGB.

This time, the terrorists are out to show that it’s not just the Russian public who are defenseless, said Pavel Felgenhauer, an independent security analyst.

“The point was to scare off foreigners, not to maybe kill them but to hit Russia’s image, (and) its economy as an investment destination,” he said.