In 1973 a crack commando unit of "killer dolphins (yes, you heard right) was created to seek mines and retrieve objects from the seafloor, but now, that unit of five have gone AWOL.

This program, started by the Soviet Navy was handed over to the Ukrainian Naval Forces after the breakup of the USSR, but, due to the Ukrainian Defense Ministry denying the existence of the program, no official word of the dolphins' whereabouts have surfaced.

According to isciencetimes.com, the abilities of a killer dolphin vary depending on who is asked. Ukrainian insiders claim the killer dolphin is capable of attacking divers, detecting mines, and planting explosives.

International Business Times states that some dolphins are even trained to wield knives or pistols that are mounted to their heads.

On Tuesday, Ukrainian and Russian media reported that five highly trained military dolphins were deployed to perform a training exercise.

However, only two of the five military trained dolphins returned to their base. Media outlets did not mention whether the three dolphins were armed.

Isciencetimes.com claim that some experts believe the dolphins might have gone to look for mates. Yury Plyachenko, a former Soviet naval trainer, told Russian state media agency RIA Novosti that dolphins often let mating get in the way of work. In fact, male dolphins are particularly vulnerable to t he charms of the opposite sex.

"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," Plyachenko said.

The Soviets and now the Ukrainians aren't the only ones, (acknowledged or not) to use or at least train dolphins.

ABC News reported that the U.S. Navy have been using bottle-nosed dolphins to detect mines and enemy divers for years.

In his memoir "The Red Circle," former Navy SEAL Brandon Webb described killer dolphin-evasion as part of his diver training.

"They train these animals to track down enemy divers, outfitting them with a device strapped to onto the head that contains a compressed gas needle. Once the dolphin has tracked you down, it butts you; the needle shoots out and pokes you, creating an embolism. Within moments, you're dead," Webb wrote. "We could tell when those little b******s were approaching because we could hear their sonar clicking - but that didn't make it any easier to escape them... [they're] way too fast for us or any other human being to outrun them," according to ABC News.