The ten people arrested by security forces during Wednesday’s raid on their alleged hideout in Yerevan plotted to kill senior Armenian officials and carry out other terrorist attacks in Armenia, the National Security Service (NSS) said on Friday.

Mikael Hambardzumian, a senior NSS official, claimed that they and 11 other individuals detained in the following days were part of a well-organized armed group. It was neutralized by Armenian law-enforcement authorities just days before committing “unprecedented” crimes, he said.

“I cannot disclose at this point what crimes they had planned and against whom,” Hambardzumian told a news conference. “I can only say that the crimes were aimed at citizens, political and state figures, and certain branches and bodies of government.”

“We could see that they had planned murders [that would have been committed] in a way dangerous to the lives of many people,” he said.

Hambardzumian, who is the deputy head of the NSS’s investigative department, compared the alleged conspiracy with the October 1999 attack on the Armenian parliament which left its speaker Karen Demirchian, Prime Minister Vazgen Sarkisian and six other officials dead.

“I can even draw parallels with what was done by [jailed ringleader] Nairi Hunanian and his gang,” he said. “But while in that [1999] case we dealt with several persons armed with several automatic rifles, can you imagine what would have happened if this group had succeeded in realizing its plans with those explosives and grenades?”

The NSS and the Armenian police claimed to have found a weapons cache when their special forces jointly raided a rented house in Yerevan’s northern Nork-Marash district. They said they found, among other things, 10 Kalashnikov rifles, 60 hand grenades, two rocket-propelled grenade launchers and a large amount of explosive materials.

The arrested people are presumably members of an obscure nationalist group led by Artur Vartanian, a 34-year-old Armenian national who is said to have lived in Spain from 1997 until his return to Armenia in April this year. The group announced its existence on social media with a video purportedly shot in Kessab, an Armenian-populated town in northern Syria that was overrun by Islamist rebels in March 2014.

The footage showed a uniform-clad Vartanian making a statement in front of nine other armed men also wearing army fatigues. He declared that they have set up the Armenian Shield Regiment to put up “armed resistance to terrorists” threatening Armenians.

The video message fueled speculation in Armenian media that Vartanian, who was also arrested on Wednesday, might be connected with Islamist militants operating in Syria. According to Hambardzumian, the NSS is now looking into such a possibility.

“We know that Artur Vartanian was in Syria,” he said. “We will work in that direction to find out what exactly he did there, what connections he has and whether organizations known to us have anything to do with this case.”

The NSS official added that Armenian security services are also looking for the sources of “tens of thousands of dollars” in funding which he said was received by the militant group. “The money was paid in Armenia but we have yet to establish its origin,” he said.

Security in and around key government buildings in Yerevan was visibly tightened following the high-profile arrests. Hambardzumian said in this regard that the NSS does not exclude that the group has other members remaining at large.