Russian military seems to have entered into a strange contract as it has bought some dolphins worth $26,000–and no one knows why.

According to Daily Mail, a tender released for the ministry unfolded Russia’s “latest military tactic” for buying the marine mammals, which will have “all teeth intact’ and no mucus from the blowhole.”

Russian Defense Ministry made an online request to buy the dolphins. But Moscow’s Utrish Dolphinarium was the only bidder who showed up.

According to Russia’s website for state tenders, by Aug. 1, Dolphinarium has promised to supply two female dolphins aged 3 to 5 years and three male dolphins. However, the site has not revealed any motive behind buying the dolphins.

The supply of the dolphins will begin at the Sevastopol, which is located in the southwestern region of the Crimean Peninsula.

There is a little prospect that the dolphins would be used as killers. It is believed that they would also be used for therapeutic purposes, locating bombs and weapons underwater, just like what’s used in multiple capacities in the past.

Dolphins have earlier been used by global superpowers to foster military operations. Russia has been incorporating the efforts of dolphins since the 1960s while recently in 2014 it used them in the annexation of Crimea.

The same year, Ukraine demanded Russia to return the dolphins, which were used in a secret programme that trained sea mammals for military purposes. It is believed to be closed in the 1990s. Further, in 2000, a report revealed that the dolphins were sold to Iran. In 2012, the program was again revived by the Ukrainian Army.

The Soviet Navy also explored military uses of dolphins at Kazachya Bukhta, near Sevastopol, by operating a research facility 44.5800°N 33.4023°E.

Not only Russia, the United States during the Cold War used dolphins to track mines, for patrolling in water and targeting enemies.

According to New York Daily News, US has used its marine programs since the Cold War, but it does not intend to use it for war purposes.