Image copyright AFP Image caption William Nguyen's family fled to the US in 1975

A court in Vietnam has ordered the deportation of a US student arrested at a recent demonstration that turned violent.

William Nguyen was found guilty of "causing public disorder".

He was detained in June at a protest in Ho Chi Minh City against new economic zones that some fear will be dominated by Chinese investors.

US Secretary of State Mike Pompeo had raised Mr Nguyen's case with Vietnamese officials.

Authorities detained more than 100 people as the demonstrations turned violent with rocks and petrol bombs. Six Vietnamese nationals have been jailed.

Mr Nguyen was to be deported immediately after the one-day trial on Friday. The US embassy in Hanoi has said it is pleased with the outcome.

"We understand from the court's decision that he will be deported after paying a fine," spokesman James Thrower told the Reuters news agency.

The maximum sentence for the 32-year old would have been seven years in prison.

Let off lightly?

"The jury acknowledged that the defendant admitted his illegal activities. Considering his sincerity, the court did not hand him a prison sentence," a state newspaper report of the court proceedings says.

Mr Nguyen, a Yale graduate from the state of Texas, was visiting Vietnam when he began documenting the demonstrations.

He joined protesters in Ho Chi Minh City on 10 June, tweeting "how enormous of an achievement" the demonstrations were for the Vietnamese people.

Image copyright Getty Images Image caption Protesters like those who marched in Ho Chi Minh City have said they will demonstrate again

According to his family and friends, Mr Nguyen was "beaten over the head and dragged into the back of a police truck". State media said he was "causing trouble" but the government has denied using force against him.

Mr Nguyen's family fled South Vietnam after its collapse in 1975.

The proposed economic law would give foreign investors 99-year leases on land in three designated special economic zones across the country.

Protesters believe the bill - the passage of which has been delayed - will allow Chinese companies to take control of Vietnamese land.

Demonstrators gathered in various parts of the country, including the major urban centres of Hanoi, the capital, and Ho Chi Minh City.

Some carried anti-China banners, including one reading: "No leasing land to China even for one day."