Iran has detained two Chinese nationals on charges of spying on its military and nuclear facilities, state radio reported Wednesday.

There have been a series of similar accusations against Westerners in Iran in recent years but none against China, with which Iran enjoys good relations.

"The Chinese nationals were detained while taking photos and recording video of a military complex in Arak city," the radio quoted Ali Reza Jamshidi, spokesman of Iran's judiciary, as saying. "They entered Iran through Kish Island as tourists."

Kish is a resort island and free-trade off the southern coast of Iran. A 40-megawatt nuclear reactor is being built in Arak, 435 miles to the north.

Jamshidi said the case was under initial investigation by the country's judicial authorities.

No further details were given.

Iran's judiciary announced Monday it had concluded its investigations into two Iranian-Americans accused of conspiring against national security. Two other Iranian Americans also are being held on security-related charges.