Members of the Organization for Security and Cooperation in Europe (OSCE) mission exit a bus for a hotel in Donetsk, Ukraine, March 12, 2014.
Members of the Organization for Security and Cooperation in Europe (OSCE) mission exit a bus for a hotel in Donetsk, Ukraine, March 12, 2014.
VIENNA - Gunmen manning a roadblock in Crimea last week threatened to open fire at an unarmed OSCE observer team if it tried to enter the southern Ukrainian region, now controlled by pro-Russian forces, a report on the failed mission said.

The mission report, obtained by Reuters, gave new detail on how more than 40 military observers from about two dozen member states of the Organization for Security and Cooperation in Europe (OCSE) were prevented from getting to Crimea.

“Despite repeated attempts to enter the Crimean peninsula... (the monitors were) consistently refused access at gunpoint and therefore were not able to dispel concerns over the reported unusual Russian Federation military activity,” it said.

However, their observations still “produced significant evidence of equipment consistent with the presence of Russian Federation military personnel in the vicinity of the various roadblocks encountered” during the March 5-8 period.

Citing the report, the United States said in a separate statement that the Russian military appeared to have been involved with the armed groups who set up road blocks and blocked the OSCE observers from crossing into Crimea last week.

Pro-Russian forces have taken over military installations across Crimea, home to the Russian Black Sea Fleet. When the OSCE team tried to get into Crimea on Saturday, warning shots were fired and it was turned back.

It was the last - and the most dramatic - of several failed attempts by the observers to enter Crimea to try to find out more of what was happening there.

The report provided a blow-by-blow account of the March 8 incident as the team attempted to reach the Crimean port town of Sebastopol but were stopped at a roadblock with “a mixture of uniformed and unidentified armed personnel”.

“Numerous roadblock personnel were observed with safety catches off,” it said. “Less than five minutes after arrival, as the team moved forward to the roadblock, a three-round burst of automatic fire was discharged within the roadblock area.”

US sees 'direct involvement' by Russia

The OSCE monitors were told there were no orders from  higher authorities to allow passage amid “alleged concerns over the influence of external actors” on the March 16 referendum in Crimea on whether to join Russia, the report said.

While in the vicinity of the roadbloack, SALW (Small Arms and Light Weapons) were “held in the aim towards” the OSCE team.

“The team were forcefully advised by the roadblock personnel that further approaches would be met with direct fire,” it said.

A UAZ 469 vehicle with license plate numbers associated with the Black Sea Fleet were seen at the site, the report said. At an earlier attempt to enter Crimea, more than 50 soldiers wearing “RU pattern uniforms and combat equipment without identifying patches” were observed.

The U.S. ambassador to the OSCE, Daniel Baer, said in the U.S. statement: “This report adds to our deep concerns and clearly suggests direct involvement by the Russian federation and its agents in preventing impartial, unarmed observers from doing the work they are supposed to do.”

Moscow, which denies its troops have a role in the takeover of Crimea, says people there - a small majority of whom are ethnic Russians - should have the right to secede. A referendum on joining Russia is to be held on Sunday.