Thousands of Moroccans have held protests in several towns and cities after a fish-seller was crushed to death in a refuse lorry trying to retrieve fish confiscated by police.
The death of Mouhcine Fikri in the northern town of Al-Hoceima on Friday drew widespread anger on social media.
His death drew parallels to that of a Tunisian fruit seller in 2010 which helped spark the Arab Spring uprisings.
Morocco's King Mohamed has ordered officials to visit Mr Fikri's family.
The interior and justice ministries have also pledged to hold an investigation.
'Everyone feels crushed'
The anti-government protests, on a scale rare in Morocco, were called by activists of the February 20 movement, who organised demonstrations during the Arab Spring in 2011.
Angry postings on social media referred to "Hogra", a term for official abuse and injustice.
"I have never seen such a crowd in the last few years, since 2011 at least," said Houssin Lmrabet, an activist in the town of Imzouren where a protest followed the funeral of Mr Fikri.
"Everyone feels crushed by that garbage truck here."
Protests were also held in Al-Hoceima, Casablanca and the capital Rabat.
Police had confiscated and destroyed Mr Fikri's swordfish because it is not allowed to be fished at this time of the year, according to Moroccan media.
Video circulating on social media appears to show Mr Fikri jumping into the back of the refuse lorry to retrieve his fish, before being crushed to death by its compactor.
Interior Minister Mohamed Hassad vowed to hold a speedy investigation into exactly what had happened.
"No one had the right to treat him like this," he told the AFP news agency.
"We cannot accept officials acting in haste, anger or in conditions that do not respect people's rights."
The incident evoked memories of Mohamed Bouazizi, the Tunisian fruit and vegetable seller who doused himself in petrol and set himself alight after officials seized his goods in December 2010.
Public outrage at the incident led to overthrow of then-president Zine El Abidine Ben Ali and the unrest spread to Egypt, Libya and other countries in the Arab world.