ISLAMABAD, Pakistan (CNN) -- Twenty people were killed early Saturday after a suspected U.S. airstrike in northwest Pakistan, a intelligence official said.

The incident occurred in South Waziristan near the Afghan border when a drone dropped two missiles on a home, according to Pakistani intelligence officials.

The U.S. military in Afghanistan routinely offers no comment on reported cross-border strikes, which are normally launched from unmanned drones.

But the United States is the only country operating in the region known have the capability to launch missiles from drones, which are controlled remotely.

CNN's Zein Basravi contributed to this report.

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