Thailand's military government warned women on Monday against posting "selfie" photos of the lower half of their breasts — a social media trend that has gone viral — saying their actions could violate the country's computer crime laws.

Thailand's 2007 Computer Crimes Act bans any material that causes "damage to the country's security or causes public panic" or "any obscene computer data which is accessible to the public."

The culture ministry said offenders faced up to five years in jail, but did not say how they would identify the culprits.

"When people take these 'underboob selfies' no one can see their faces," ministry spokesman Anandha Chouchoti said.

"We don't know who these belong to and it encourages others to do the same.

"We can only warn people to not take it up. They are inappropriate actions."

The ministry has long been criticized for being overzealous in its censorship of films, music, television and some Western cultural practices in an attempt to preserve traditional values in a country that is also infamous for its raunchy night life.