Derrik Sweeney, of Jefferson City, Mo., was among three American students arrested this week in Cairo.
Kevin Sweeney says his son called about 6:30 a.m. on Wednesday from the phone of a U.S. Embassy official before additional questioning and spoke "very briefly" with his mother Joy Sweeney. The teen said he hasn't been hurt.
An Egyptian official has said Sweeney and two other students were arrested on the roof of a university building where they were throwing firebombs at security forces fighting with protesters near Tahrir Square.
Kevin Sweeney says his son said he was watching the demonstrations but denies throwing anything.