Since 1 April, 38 people have been killed in clashes between police and demonstrators protesting against President Nicolas Maduro in the Venezuelan capital, Caracas.
In recent days, protesters have added pots filled with excrement to their armoury and in a play on words have called them “poopootov cocktails”.
Warning opposition supporters to stop using the faeces-filled missiles, judicial inspector general Marielys Valdez described the pots as a “chemical weapon”.
She said: “The use of biochemical weapons is fully classified as a crime and incurs strong penalties.
“The use of chemical weapons, in this case human and animal faeces, has consequences.
“It can get into the water and cause terrible contamination.”
One protester said he was using “poopootov” bombs because riot police “repress us with Molotov cocktails, with pellet guns…and this is our only way to throw something at them”.
He said: “The government is arbitrarily attacking us, whereas we are seeking a way to protest that we need a change of government.”
Protesters are demanding early elections and accuse Mr Maduro of running a dictatorship.
They also blame the president for an economic crisis that has caused shortages of food and basic supplies, like toilet paper.
The South American country has the world’s largest oil reserves and once commanded a booming economy, but many Venezuelans accuse Mr Maduro of pilfering the nation’s wealth.
Despite severe economic shortages, it emerged last month that the president donated $500,000 (£388,000) to Donald Trump’s inauguration fund.
Mr Maduro has blamed the crisis on what he calls a US-backed plot and described the protesters as “terrorists.”
Last week, Venezuela’s ruling party was forced to play a video of jailed opposition leader Leopoldo Lopez on state TV after rumours spread that he had died in prison.
Lilian Tintori, Mr Lopez’s wife, has accused the government of “kidnapping” the activist and former mayor in an attempt to stop the protests.
In February, Mrs Tintori met US President Donald Trump, who called on the Venezuelan government to release Leopoldo Lopez “immediately”.