Pro-Russian troops who seized control of an air base in Crimea threatened to shoot Ukrainian soldiers at the installation Tuesday -- but the warning didn't stop the local servicemen from playing soccer nearby.

Ukrainian military personnel who were lying prone at Belbek base had guns pointed at them, according to James Mates, a correspondent with NBC News' British partner ITV News.

Earlier, the pro-Russian troops who had taken control of Belbek fired warning shots into the air as around 300 unarmed Ukrainian soldiers, who previously manned the airfield, demanded their jobs back.

About a dozen soldiers at the base warned the Ukrainians not to approach. They said they would shoot the Ukrainians if they continued to march toward them.

The warning shots were apparently the first fired since Russian troops — estimated by Ukrainian authorities to be 16,000 strong — tightened their grip on the Crimea Peninsula over the weekend.

However, ITV News producer John Angier reported that an impromptu game of soccer helped to calm the atmosphere by around 1:30 p.m. local time (6:30 a.m. ET).

The Ukrainian troops eventually backed down and left the site, Mates reported.

The Associated Press contributed to this report.