Police say a 73-year-old man was badly burned after he opened a mysterious package the shape of an oatmeal container left on his doorstep and it exploded.

Chief of Detectives Robert Boyce says the man had second- and third-degree burns to more than 80 percent of his torso and legs, and was hospitalized in critical condition.

Boyce says the explosive was rigged to detonate when opened. He says the blast left behind “substantial evidence.”

Neighbors told reporters the man was doubled over in flames and was on fire when emergency crews arrived.

The victim owns the Queens building but doesn’t live there. A building tenant said he saw the package but didn’t open it because it wasn’t addressed to him. Police didn’t think it had been sent through the mail.

(AP)