MADISON, Wis. -- Madison police conducting a drug investigation at a house on Madison's east side shot a dog before taking two men into custody.

Madison police said they came to a house in the 2500 block of East Johnson Street, just a few blocks from Emerson Elementary School and Madison East High School, Wednesday afternoon as part of a drug investigation.

"I saw the one squad car pull up in front and two guys got out, and then a man came out of the house," said neighbor Chuck Busbuy, who witnessed the incident.

Police said during the investigation someone ran inside the house and up to the second floor apartment.

Police said that officers followed, and at the top of the stairs they found an angry and aggressive dog, which was fatally shot by an officer.

"Two more squads came, and they kicked in the door, and there were two shots and everybody was on the ground," Busbuy said.

"Two shots were fired. The dog was stopped and that nobody was injured," said Lt. Brian Ackeret, of the Madison Police Department.

Police said the two men who were detained will likely face charges, pending a search of the house.

Police said they saw marijuana inside on their security sweep but waited to search until they got a warrant.

Authorities began a search of the property Wednesday night.

Stay tuned to WISC-TV and Channel 3000 for continuing coverage.