US President Barack Obama joked Wednesday that even he would get shot if he lost his keys and tried to break into the White House.

He was answering a question about the arrest of his friend, prominent African-American Harvard scholar Henry Louis Gates, who was hand-cuffed and detained after having to break into his home in the Massachusetts town of Cambridge.

"I guess this is my house now. So it probably wouldn't happen," Obama said, looking around the ornate East Room and trying to put himself into a similar situation. "But let's say my old house in Chicago," he continued.

"Here, I'd get shot," he quipped, to laughs from the gathered press corps.

Turning serious though, the nation's first African-American president castigated Cambridge police for the incident.

"Now, I don't know, not having been there, and not seeing all the facts, what role race played in this," Obama told a press conference.

"But, I think it's fair to say, number one, any of us would be pretty angry. Number two, that the Cambridge police acted stupidly in arresting somebody when there was already proof that they were in their own home."

Cambridge police have already apologized to Gates, a leading expert on African-American relations, for the incident in which he was handcuffed outside his front door and spent four hours in detention.