Scifi/Horror Story about words openning a portal

[rossbrown]

I read a spectacular short story many years ago and I can't find it again. It goes something like this:

Scientists discovered that words do have power. By speaking the right words, they accidently opened a portal into another world. They could see two children playing in a yard with a house on it. The children couldn't see them though. They new they could pass objects through the portal because they threw some small pebbles across to the other side in such a way that the children wouldn't notice but the scientists could see them on the lawn. Since they opened it by accident, they didn't know how long the portal would remain open. While they were debating on what to do, one of the scientists jumped across the portal on his own. Well, the children immediately noticed him. They started to approach him and they smiled revealing very large inhuman teeth. They attacked him and killed him and proceeded to eat the scientist leaving nothing but bones.

A man, apparently seeing this through a window came out of the house. He was dressed somewhat like a priest and held a bible like book. He started reading from the book and the portal vanished. The priest on the other side apparently opened a new portal but one that they could see the scientists but the scientists couldn't see them, sort of a reverse of the original situation. The scientists knew that because the leftover bones from the eaten scientist started falling on the ground where the portal had been . The children must have been throwing them through the portal just like the scientists were throwing the pebbles. Story Ends

Anyone ever heard of this story? I think it must be very old. I probably read it in a book like Best Science Fiction of the year. I used to have some very old ones.