Calgary police are investigating eight explosive devices found on light rail and freight train tracks. (CBC)

The Calgary police bomb squad detonated several explosive devices found near LRT and freight train tracks in the city's south Monday night.

A Calgary Transit employee found the devices between the Heritage and Southland C-Train stations and called 911. All trains were halted in the area for several hours, said police Tuesday.

Some explosive devices were also found near a rail line parallel to the LRT, said police.

At a news conference Tuesday, police described the eight devices as similar to "pipe bombs." Two of them had already been detonated, while the bomb squad triggered the other six.

"These kind[s]of devices would not have caused any disruption to a rail line, to a train, or anything else that was passing by, to a vehicle," said duty Insp. Terry Larson.

'I don't think it's targetting any infrastructure like the LRT line, if that's what you're wondering.'—Insp. Terry Larson

He said the explosives may have been thrown over the fence near the tracks simply because it was a secluded area.

"If you're thinking of a targeted event, I think it's just a place where it's concealed ... so I don't think it's targetting any infrastructure like the LRT line, if that's what you're wondering."

Police said the explosives could have seriously hurt anyone who might have picked them up.

"Our police explosive technicians sent the components away to be investigated. We're looking at fingerprinting, obviously chemical analysis of any components, all that sort of thing," said Larson.

Ron Collins, spokesman for Calgary Transit, said passengers were never at risk.

"This is the first time we have seen something like this placed on our tracks, but it is a little worrisome," he said.