Two people were injured and Michael Schmidtanother four remain unaccounted for after a house exploded in New Jersey on Thursday, police said.

Police responded to reports of a house fire around 10:35 a.m. ET in the South Jersey town of Buena, according to Franklin Township Police Chief Matt DeCesari. The incident was confirmed to have been an explosion, he said.

An infant was removed from the residence and was being transported to a burn center in Pennsylvania, DeCesari said. A woman believed to be in her 20s or 30s was also taken to a burn center with non-life-threatening injuries, he said.

Four people remain unaccounted for following the blast, DeCesari said.

"We have not determined where these four people are," he said.

The individuals are believed to be mostly from one family, though a friend may have been staying at the house, DeCesari said.

Several houses on the block sustained damage in the explosion but all residents have been evacuated and there were no additional injuries, DeCesari said.

The investigation is being deemed a criminal one at this early stage, DeCesari said.

"It was an explosion, we don't know what caused it," DeCesari told reporters at a press briefing Thursday afternoon. "We are treating it as a criminal investigation at this point until we determine otherwise."

Multiple fire departments responded to the scene and the Bureau of Alcohol, Tobacco, Firearms and Explosives was also en route, DeCesari said.

Footage from the scene showed the home had been reduced to debris. A person who works nearby told Philadelphia ABC station WPVI he heard a loud "boom" and felt the explosion, then saw smoke coming from the house.

"This is just something that's very tragic," DeCesari said. "This is a small community. Everybody seems to know each other. And when you have an incident like this, it really hits everyone."