Ukrainian "attack" dolphins may be on the loose and looking for love, according to a source familiar with the country's rumored secret military training program.

On Tuesday, Russian state media agency RIA Novosti reported that three dolphins had escaped from a Ukrainian naval training base in Sevastopol on the Crimean peninsula. The mammals were possibly in search of suitable mates.

The outlet quoted a "former Soviet naval anti-sabotage officer" as saying this type of thing had happened during dolphin training programs during the 1980s.

"If a male dolphin saw a female dolphin during the mating season, then he would immediately set off after her. But they came back in a week or so," Yury Plyachenko told RIA Novosti.

The news organization made international waves last year after it reported 10 dolphins were being trained by the Ukrainian navy to detect mines and attack enemy swimmers. However, Ukraine's Defense Ministry has denied reports of any attack dolphin program, RIA Novosti notes.

While often unconfirmed, rumors about military-trained dolphins have existed for decades.

Wired reports that the Soviet Union originally controlled the dolphin program at Sevastopol, but it was turned over to Ukraine after the Cold War.

Soviet dolphins also eventually ended up in Iran, according to a BBC report from 2000. At the time, the news outlet reported that a collection of trained creatures -- including dolphins, walruses, sea lions, seals, and a white beluga whale -- were sent to the Persian Gulf after their caretaker said he ran out of money to feed them.

At least some of those mammals had been trained to attack enemies with weapons including harpoons, according to the BBC, and "could also undertake kamikaze strikes against enemy shipping carrying mines."

The United States Navy has trained animals through its own Marine Mammal Program for decades.

According to PBS Frontline, dolphins helped the Navy during the Vietnam War and in the Persian Gulf:

The dolphins would swim slowly, patroling the area with their sonar, and alert armed trainer guards if they located a swimmer. They are also trained to "tag" the enemy swimmer with a marker so that Navy personnel can apprehend him.

However, on its website, the U.S. Navy Marine Mammal Program categorically denies that any of its dolphins were ever trained to kill, writing that "the Navy does not now train, nor has it ever trained, its marine mammals to harm or injure humans in any fashion or to carry weapons to destroy ships."

The site adds that such a move would be dangerous to everyone involved, as "dolphins cannot discern the difference between enemy and friendly vessels, or enemy and friendly divers and swimmers."