Law-enforcement authorities investigating Armenia’s deadly post-election strife have dropped controversial coup accusations leveled against four prominent opposition politicians allied to former President Levon Ter-Petrosian, it was announced on Wednesday.

Aram Sarkisian, Ararat Zurabian, Karapet Rubinian and Gurgen Yeghiazarian were charged with attempting to “usurp state authority” and provoking “mass disturbances” in Yerevan for that purpose following the March 1 violence in Yerevan. Zurabian, Rubinian and Yeghiazarian were also arrested and released from jail pending investigation last summer. Sarkisian was never taken into custody despite playing a larger part in the Ter-Petrosian-led opposition movement.

Vahagn Harutiunian, a senior official from the Special Investigative Service (SIS) leading the criminal inquiry, said he decided to drop the accusations late last week because of a lack of evidence of the four oppositionists’ involvement in what the investigators call an opposition attempt to stage a coup d’etat. He had earlier insisted that there are sufficient grounds for keeping the three of them in detention.

The development was announced just two days before the start of a high-profile trial of seven other well-known opposition figures facing the same coup charges. Among them is Aleksandr Arzumanian, Ter-Petrosian’s presidential election campaign manager, and three parliament deputies. All of them deny the accusations.

Harutiunian said that the investigators have still a long way to go in completing one of the most extensive criminal inquiries ever conducted in Armenia. In particular, he said, they have yet to determine just how justified the actions of police and other security forces were on March 1.

Two police officers and eight civilians were killed on that day as they tried to disperse thousands of opposition supporters protesting the alleged rigging of the February 19 presidential election. Ter-Petrosian and his entourage say the authorities deliberately used lethal force to quell the protests.

Harutiunian admitted that the investigators have still “a lot of work” to do in ascertaining the circumstances of the civilian deaths. He said they presently have no evidence to charge anyone in connection with those deaths.