Gunmen opened fire at the Crimean frontier today as a group of unarmed military observers arrived Saturday, forcing them to withdraw on their third attempt to enter Crimea, a source familiar with the mission says.

The unarmed observers, who represent members of the Organization for Security and Cooperation in Europe, had hoped to spend a week conducting the first independent attempt at verifying military activity in the disputed region. But as they arrived, they were met with gunmen who fired warning shots. It isn’t clear if they were meant for the observers or someone else.

Still, it was “a very tense standoff,” wrote the source, who did not want to be identified. “They aimed unsafed weapons in our faces. “After two bursts of automatic fire were fired over our heads, we withdrew.” The OSCE said no one was hurt in the incident.

2 Canadians among group

The 47 military and civilian observers come from 25 countries including Canada.

Two Canadians are members of the armed forces who are specialists with “the necessary training and experience to undertake missions of this nature,” said Julie Dimambro, a spokeswoman for the Canadian Forces. She would not comment further on their identity citing security concerns.

Crimea checkpoint

Armed gunmen stopped the Organization for Security and Cooperation in Europe from entering Crimea on Thursday at a security checkpoint. (CBC News)

The observers first tried to enter Crimea on Thursday. In an arduous land journey that lasted 12 hours on buses, with Ukrainian military escort, the observers were turned away by gunmen at two possible entry points to the peninsula.

On Friday, the observers tried a “more assertive” attempt at entering, but again, gunmen armed mostly with Kalashnikov assault rifles turned them back. Even while being barred, the unarmed monitors have already observed evidence of Russian presence.

The source told CBC “without a doubt” some of the gunmen they have encountered were Russian.

Crimea OSCE

Members of the group representing the Organization for Security and Cooperation in Europe hope to spend a week looking at military activity in Crimea.

The mission was conceived under provisions that allow any OSCE member country to invite independent observers to dispel concerns “unusual military activity.”

The OSCE says Ukraine requested the mission. Those provisions require all signatories to “share information on their military forces, equipment and defence planning.” Russia is also a member of the OSCE.