DENVER – Police searched Friday for two men who used a pump sprayer to douse four people with a flammable liquid at a Denver apartment and then set them on fire.

One woman was seriously injured in the attack that rattled a northwest neighborhood.

“Who would do something like this? What kind of animal is he?” Maria Gomez, a neighbor who did not know the victims, told the Denver Post.

The men came to the door of the apartment on Thursday night, police spokesman Sonny Jackson said. A woman who answered the door was sprayed with a liquid by one of the men and another threw a lighter on her, said Raquel Lopez, a police spokeswoman. The men then set fire to two men and another woman inside the home.