ROARING SPRING, Pa. (AP) -- Someone is killing ducks with blow-gun darts and target arrows at a popular southwestern Pennsylvania pond, the Pennsylvania Game Commission said. The mysterious killings have been going on for about two weeks at Spring Dam Park in Roaring Spring, according to WJAC-TV (http://bit.ly/OpZJod ). The spring-fed pond is in southern Blair County, about 80 miles east of Pittsburgh. The darts being used to shoot the ducks are made of wood or steel, some of which are 4 inches long. Officials haven't said how many ducks have been killed, but some carcasses and darts could be seen sticking up out of the still-thawing mud on Thursday. Wildlife officer Albert Zellner said children come to the pond and "want to feed the ducks and look at the fish and that's a 4-inch piece of sharpened steel. You don't need that here." Joseph Dively, a frequent park visitor, agreed. "It's a hot spot through the summer and even through the winter, there's always someone here," Dively said. As for the duck killings, "There's a season for that and I don't think it's right what's going on." Zellner explained that the birds are not just being killed illegally, but also cruelly. "It's not a killing shot initially, it just wounds it," Zellner said. "The duck jumps in the water, he can't fly, he can't get away and he just ends up dying in the water. It's a slow and painful death." Local ordinances ban the use of weapons in the park. Whoever has killed the birds also could face state wildlife charges.