Iraq's prime minister has expressed doubts that the three Americans who went missing from a Baghdad neighborhood last week have been kidnapped.

Haider al-Abadi says no demands have been made for the three and that they were most likely taken by "criminal gangs."

Al-Abadi spoke on Friday from Davos, Switzerland, where he is attending the World Economic Forum.

He says the Iraqi government doesn't "know that they (Americans) have been kidnapped. They are missing" and Iraqi security forces are searching for them.

The U.S. Embassy in Baghdad has confirmed that an unspecified number of Americans are missing and said it's working with Iraqi authorities to locate them.

Baghdad authorities said the Americans were kidnapped from a "suspicious apartment," and provided no other details. There has been no claim of responsibility.