Tampa-based group of military veterans says it's helping Americans evacuate Ukraine

After a month of warning U.S. citizens to leave Ukraine immediately, the U.S. says it will not be sending troops to rescue Americans fleeing the country out of concerns that such military action could escalate to an all-out war.

Meanwhile, a privately-run evacuation operation is underway. Project Dynamo is a non-profit organization made up of volunteers, many of them current and former military members with experience in special operations and intelligence.

The organization released an urgent update overnight Thursday, urging all Americans seeking removal from Ukraine to register immediately. The group said registering citizens should include reliable contact information as communications are likely to go down.

Days before Thursday's Russian military invasion of Ukraine, Project Dynamo reported having boots on the ground in Kyiv, saying over the weekend that it was preparing for a potential evacuation. That planning and coordination intensified after the U.S. State Department evacuated diplomatic personnel and abandoned the U.S. Embassy in Kyiv in mid-February.

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As reports came in of explosions in Kyiv overnight, organizers told FOX 13 News Thursday that one of their operators on the ground felt the blasts near Kyiv and knew at that point it was time to start evacuating Americans.

"Project Dynamo is currently conducting the very first rescue of Americans, approximately 28 that we're actively working as we speak," Project Dynamo spokesman James Judge said.

One of those Americans was a woman who lives in New Mexico and had returned to Ukraine for her father's funeral this week. Project Dynamo told FOX 13 the woman did not anticipate the situation would escalate this quickly and now needs to get out.

Airspace is shut down to commercial flights as armed Russian troops roll across the border.

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The nonprofit said it began initial plans for operations in Ukraine in January. According to the organization, Project Dynamo recently intervened in Afghanistan by physically inserting team members into the Taliban-controlled country to conduct rescue operations of Americans stuck in the region.

"American team members from Dynamo entered Afghanistan and escorted American men, women, and children past Taliban checkpoints to secret safe house locations before helping them to board transports bound for the U.S.," the organization said.

U.S. officials estimate that as many as 30,000 Americans living in Ukraine.

If you have someone there who needs help evacuating, you can make a request on Project Dynamo's website