Trinh Ba Phuong, 35, Trinh Ba Tu, 31, Nguyen Thi Tam, 48, and 58-year-old Can Thi Theu were arrested Tuesday in Hanoi and the nearby Hoa Binh Province.

The four are being investigated for "making, storing, spreading information, materials, items for the purpose of opposing the State of Socialist Republic of Vietnam," Vietnam’s Ministry of Public Security said Thursday.

Police accused them of "drafting, posting and distributing videos and articles with distorted content for the purpose of sabotaging the state."

When police forces raided Phuong’s home in Hanoi, he stood his ground inside the house, forcing the police to break down the door, the ministry said.

Phuong’s Facebook account, which had attracted more than 50,000 followers, carried distorted information and livestreamed comments about the clash that took place in Dong Tam Commune in My Duc District, 40 km (25 miles) south of Hanoi, police said. Three policemen and a civilian died in the confrontation.

In another case, police in Khanh Hoa Province detained a 44-year-old woman identified as Nguyen Thi Cam Thuy on Wednesday for using Facebook to carry out anti-state propaganda.

A raid of her home found 150 liters of gasoline in five plastic cans, bullets, four gas cylinders, many knives and machetes allegedly for use against the state's functional forces.

Between April 29 and May 3, Thuy posted articles and videos with "distorted" content against Vietnam's Communist Party and the State, police said.

Under Vietnam’s Penal Code, anti-government propaganda can be punished with up to 20 years in jail. Several people have been imprisoned for the offense in recent years.