The crisis in Syria is posing serious security threats to southeastern European countries, Colonel Georgi Milanov, deputy director of Bulgaria's National Intelligence Service, said here on Wednesday.

"Currently, the majority of the risks and threats of terrorism to the countries of Southeast Europe is related rather to external factors or crisis developments," Milanov said during a keynote report at the 11th International Conference "Security in Southeast Europe -- in Search of Smart Solutions."

Some of the potential risks and threats to the security of the countries of Southeast Europe derived from the escalating crisis in Syria, he told the conference also attended by Bulgarian President Rosen Plevneliev.

According to Milanov, the Syrian crisis involved many foreign elements, as the recruitment of radicalized elements continued in Southeast Europe with the participation of local extremists.

Some extremists have received military training in neighboring countries of Syria, and have been transferred to the Syrian territory, he said.

"These elements can generate serious asymmetric risks to the security of the countries in Southeast Europe after they return having a real combat experience and extremist ideological indoctrination," Milanov said.

Based on the data and analytical assessments available at the National Intelligence Service, it expected that the main existing and potential risks and threats to the security of the countries in Southeast Europe would continue to exist next year, Milanov said.