Both the agencies said the quake struck about 88km north of the capital, Dili, at a depth of approximately 11km.
East Timor lies in the so-called Pacific Ring of Fire where earthquakes are frequent.
"The tremor was very strong and shook everything in my house," the Reuters news agency quoted Ruben Ximenes, a technician for the United Nations in Dili, as saying.
"All I could do was run away."