BANGKOK (Reuters) - A British journalist was charged with arms possession on Tuesday after being arrested at a Thai airport for checking in flak jacket plates and gas masks, standard equipment for media heading into war zones and other hostile environments.

Anthony Cheng, 46, and German freelance journalist Florian Witulski were detained at Bangkok’s Suvarnabhumi Airport on Monday, before they could board a flight to Iraq via Turkey for an assignment for China-based broadcaster CCTV English.

Thailand’s Arms Control Act stipulates that gas masks and ballistic vests are war weapons and those carrying them need a license.

In August 2015, a Hong Kong photojournalist was arrested at the same airport for carrying body armor and a helmet. Charges were later dropped.

Cheng was carrying three gas masks and four plates for safety vests, said Somchart Maneerat, a police investigator.

“He faces a charge of unlicensed possession of war weapons,” Somchart told Reuters, adding that he faced up to five years in prison if found guilty.

Cheng was released on bail of 100,000 baht ($2,930) on Tuesday. Witulski, 31, was released early on Tuesday.

Witulski told Reuters the men were not aware that licenses were required for the safety gear.

“The plates were loose and were taken as check-in baggage, as we have done before many times,” Witulski said, adding that he and Cheng had traveled to Iraq and Afghanistan several times carrying plates, without being stopped by Thai authorities.

The Foreign Correspondents’ Club of Thailand urged Thai authorities to drop the charge against Cheng, saying it has offered to work with the government to allow journalists to carry protective equipment.

“Under the present implementation of the 1987 law, they are presented with an invidious choice: break Thai law or increase the risk to life and limb,” the body said in a statement.

“It is worth recalling that two foreign journalists were killed in the violence in Bangkok in 2010; both might have survived had they been wearing body armor.”

In 2010, Reuters cameraman Hiro Muramoto and Italian freelance photographer Fabio Polenghi were shot dead, while covering clashes between anti-government protesters and Thai troops in the capital.