(CNN) -- At least 20 soldiers in the Tajik Defense Ministry were killed Sunday in an attack in the Rasht district of Tajikistan, the Russian news agency Interfax reported, citing a source in the Tajikistan government.
"There are a lot of victims," the source told Interfax. "You can stay about 20 dead now, but I think the number of dead will rise."
The soldiers' military convoy was heading to an outpost in the district, where it was thought that a number of criminals who were hiding after they escaped last month from a detention facility, Interfax said. The soldiers, who were to search for the inmates, were fired on in the Komarob gorge, near the border with Afghanistan, on the way, according to the news agency. Of the 25 inmates who escaped, only seven have been apprehended.
Tajikistan Defense Minister Sherali Khayrulloyev flew to the gorge site by helicopter, Interfax reported, and more soldiers were also headed there.
There was no official confirmation of the incident from Tajikistan authorities, according to the news agency.
CNN's Bruce Conover contributed to this report.