Witnesses said many police were present May 8 but did nothing to stop the attack on about a dozen nuns. The guards "insulted and attacked the nuns with batons," reported ucanews.com. The previous night, workers had taken trucks and tools to the site, which is next to the nuns' current convent.

The nuns said their congregation had taken legal ownership of the 2,152-square-foot plot of land in 1949, but the communist government took it over in the 1950s. Authorities later divided the site and sold it to other people.

Ucanews.com reported the nuns have asked the government to return the land many times over the years. In 2016, Hanoi resident Tran Huong Ly hired workers to build a house on the land after telling nuns that local authorities had granted her a building permit and a certificate to use the land.

The government ordered Ly to stop building after the nuns petitioned government authorities to deal with the case.

After being attacked May 8, Sister Cecilia Pham Duong Quynh and other nuns marched to the headquarters of the People's Committee of Hoan Kiem district to petition the district to stop the construction. They raised banners reading "Stop construction on the land of St. Paul Sisters."

Sister Quynh said officials refused to make any decision on the nuns' demand. She said they would continue marching to government bodies to ask them to deal with the illegal construction.

The Vietnam-based Association to Protect Religious Freedom said it "strongly condemns violent actions against the nuns and calls on authorities to probe the attack."

The association said Hanoi authorities should fairly examine the nuns' demand to avoid causing a bad influence on religious activities.