An American citizen is being held in Vietnam for "disrupting public order" after he joined violent protests over a controverial special economic zone draft law, an official said Thursday.
William Anh Nguyen, 32, took part in one of several rallies in the communist country on Sunday, where protesters accused the government of planning to grant China lengthy land leases in the zones.
More than 100 people were detained in southern Binh Thuan province after demonstrations quickly spun out of control when rioters lit cars on fire and damaged government property.
Large crowds who gathered in Ho Chi Minh City, including Nguyen, who was arrested Sunday and is being held for "disrupting public order", Foreign Ministry spokeswoman Le Thi Thu Hang told reporters Thursday.
"A consular visit for this individual is under arrangement and there was no use of force concerning this individual," she added.
A family friend citing relatives confirmed that Nguyen, a Texas-born Yale graduate, was detained Sunday in Ho Chi Minh City during the protests.
Nguyen, who is set to receive a Masters degree in Singapore next month, had arrived in Vietnam on Saturday.
He tweeted photos of huge crowds demonstrating in Ho Chi Minh with the caption "This is #democracy in #Vietnam".
He also posted a photo of a man on the ground surrounded by crowds and wrote: "Police struck a protestor and chaos has broken out".
The US embassy in Hanoi said it was "aware of media reports that a US citizen was arrested in Vietnam", spokesman Pope Thrower told AFP.
"When a US citizen is detained overseas, the US Department of State works to provide all appropriate consular assistance," he added in a statement.
The weekend demonstrations -- rare in the one party-state where public protests are banned or quickly broken up -- forged ahead in several cities, including the capital Hanoi, even after the government said it would delay a vote on the special economic zones.
The draft law, which made no specific mention of Chinese investors, originally proposed land leases of 99 years but the government later said it would reduce the rental terms.
Hanoi and Beijing have had a dicey relationship since a deadly border war in 1979. Tensions flare frequently between the communist neighbours over disputed claims in the resource-rich South China Sea, most of which Beijing says it controls.
Deadly protests erupted over the hot-button issue in 2014 when Beijing moved an oil rig into waters claimed by Vietnam, prompting violent riots that killed several Chinese nationals.
Demonstrators in Vietnam accuse the government of planning to grant lengthy land leases to China, a claim that prompted violent protests on the weekend