FAIRBANKS -- The predator control program in which wolves were killed by shooters in helicopters has been temporarily halted in the game area near Tok, state game officials said.

As of Thursday, 66 wolves had been killed in the Department of Fish and Game's aerial program, short of the goal to kill 150 wolves, the Fairbanks Daily News-Miner reported.

An animal rights group, Defenders of Wildlife, filed a request for an injunction this week, saying the hunt is illegal because the Board of Game earlier this month approved the program during a regularly scheduled meeting.

The group contends that means the aerial hunts could not start before July 1 since they were not approved during an emergency meeting.

A spokeswoman for the Department of Fish and Game said the hunts would continue until the court issued a decision.

However, just a day later, the hunt was halted.

The agency's Fairbanks regional supervisor, David James, said it had nothing to do with the injunction request. Rather, it's stalled by a lack of snow and money.

James said the department had $100,000 set aside for the program and had used about 80 percent this week.

He says it will take "more money and more snow" to restart the program.

James said the department will use the break to analyze the results of action taken so far and decide what areas to target next, if any.

Since the department killed fewer than half the number of wolves that it was hoping to, that is proof there aren't as many wolves in the area as biologists estimate, said Wade Willis, the Alaska representative for Defenders of Wildlife.

"They couldn't find any more wolves to kill," Willis told the Fairbanks Daily News-Miner. "They ran out of wolves; it's plain and simple."

Defenders has been opposed to the state's predator management policies and has targeted Gov. Sarah Palin's support in ads and on a special Web site. The group has long maintained that the department inflates its wolf population estimates to allow more wolves to be killed.

"They want that population estimate to be as high as possible," he said.

James said the department is confident in its population estimates and will use information gathered from tracking flights this week to "confirm or readjust what the population estimate was last fall."

He said it's possible the department will find that enough wolves have been taken to meet the program's objective, but doubts it.

"In the majority of our experience, when we've gone in and got more information to see where we stand, it's been very consistent with where we thought we were," he said. "Each step of the way, as we get additional information, we sit down and analyze it to convince ourselves we're still within the program's guidelines.

"I'm very confident in our ability to do this right and not exceed the population level that's stated in our management plan," he said.

The state estimates there are about 400 wolves in the Fortymile area and the management objective is approximately 100 wolves.

Adjacent to this control area is the 2.5 million-acre Yukon Charley Rivers National Park and Preserve. The National Park Service has expressed concern about the aerial hunt because some federal officials have expressed worry that some of the estimated 30 wolves that are the subject of biological studies in the preserve would be killed.

State officials agreed not to shoot any wolves wearing radio collars and limited the number of non-collared wolves shot in some packs. The radio frequencies of the radio-collared packs were also provided to the helicopter teams.