TEHRAN (AFP) – The Iranian judiciary on Sunday upheld a 10-year jail term for an American citizen, two US-Iranian dual nationals and a Lebanese citizen for “collaborating” with the US government.

The Tehran prosecutor’s office said their appeals had been rejected, in a ruling that came at a time of rising tensions with Washington since President Donald Trump came to power.

Xiyue Wang, a Chinese-born American, was sentenced to 10 years in jail for “collaborating with foreign governments”, said Tehran prosecutor Abbas Jafari Dolatabadi, quoted by the mizanonline website close to the judiciary.

He said the same sentence was upheld against two dual nationals for “collaborating with a foreign government”, while Lebanese national Nizar Zakka, a US permanent resident, was handed a 10-year term for working with the American government.

The US State Department in July called on Iran to immediately release US citizens and other foreigners detained on “fabricated” national security charges, after Tehran said an unnamed American had been sentenced to 10 years in prison.

“We call for the immediate release of all US citizens unjustly detained in Iran so they can return to their families,” a State Department official said.

He did not refer to specific individuals, but the call followed an Iranian announcement that an unidentified American had been sentenced for alleged “infiltration” of Iran.

?”The Iranian regime continues to detain US citizens and other foreigners on fabricated national security-related charges,” the official said.

“The safety and security of US citizens remains a top priority. All US citizens, especially dual nationals considering travel to Iran, should carefully read our latest travel warning.”

Relations between Washington and Tehran have been severed since April 1980 in the wake of Iran’s Islamic revolution, and tensions have sharpened since Trump came to power in January, especially over Iranian missile tests.

Tehran and world powers, including Washington, signed a July 2015 accord curbing Iran’s nuclear programme in exchange for a lifting of sanctions.

Although it has imposed new unilateral sanctions over Iran’s missile programme, Washington has so far honoured the nuclear accord despite Trump’s threats as a candidate last year to “rip it up”.