Provincial conservation officers are concerned about the illegal killing of bighorn sheep in B.C.'s Thompson-Nicola region after five of the animals were reported shot within four days.

Early last week, someone shot and dumped two Rocky Mountain bighorn rams near Lytton

Just days later, on Friday, a rancher reported finding the carcasses of three California bighorns near Clinton, northwest of Kamloops. Just as in Lytton, 120 kilometres away, the animals had been shot and then abandoned.

Bob Butcher, a conservation services officer in Lillooet, said the latest shooting is especially troubling.

"There's absolutely no reason for it," he said.

He said the killed sheep were from a herd that wasn't doing particularly well.

"There's illness problems. There's lamb survival [problems] in the spring," he said.

Butcher also said there is no indication that the two incidents were linked, other than the fact that "some idiot" was involved in each. He called both shootings a waste of wildlife, and hopes the culprit or culprits are found soon.

"In most of these cases, you know, somebody that does such a stupid thing is also too stupid to keep their mouth shut," he said. 

"So hopefully they have told somebody, and that somebody doesn't like what they have heard and is able to help us put an end to it," Butcher said.

Butcher said it is extremely rare for people to kill bighorn sheep for target practice.

B.C. does allow hunting for bighorn mountain sheep in the Lytton and Clinton areas, but a hunting schedule posted online shows that the regular 2011 season for bighorns in those areas closed on Oct. 20.

The B.C. Ministry of Forests, Lands and Natural Resources Operations also requires that bighorn sheep hunters are properly licensed and that they present the killed animals to regional inspection centres as part of the provincial management program.

With files from the CBC's Brady Strachan