Residents of Nenoksa, the village closest to the incident, were told to leave on a special train that would be sent to their community, TV29, a local news outlet, reported on Tuesday. It attributed the move to events at the nearby base from 5 a.m. to 7 a.m. on Wednesday, but did not elaborate on those events or explain the time frame.

The civil authorities in a nearby city, Severodvinsk, said in a statement to Interfax that the population of the village had been advised to be out of the area by Wednesday because of unspecified “planned activities” at the military testing range.

“The leadership of the Nenoksa testing range informed us of planned activities of the military authorities,” the statement said. “In this connection, it was advised that residents of Nenoksa depart the territory of the village from Aug. 14.”

There was no indication when it might be safe for them to return.

Later on Tuesday, however, a report on Interfax suggested that the evacuation might have been called off. It quoted an anonymous official in the Severodvinsk city administration as saying, “Yes, indeed, they informed us the military had canceled tomorrow’s activities.”

President Vladimir V. Putin boasted last year that Russia was testing a cruise missile that would be propelled by a small nuclear reactor, in addition to carrying a nuclear warhead, flying a path too unpredictable to be intercepted. Western analysts called the missile “Skyfall,” and on Monday, President Trump tweeted that the accident last week was a Skyfall exploding.

The Russian authorities have not said that the new type of weapon was linked to the accident. But they have acknowledged that radioactive material and a reactor were involved in the incident at a missile testing range.

Russian statements about the intensity of the radiation release have been contradictory. Scientists with the Russian Federal Nuclear Agency said on Sunday that radiation levels had climbed briefly to twice the background level in Severodvinsk, about 25 miles from the test site.