CASABLANCA, Morocco- Tens of thousands of Moroccans took to the streets of Casablanca on Sunday in the largest opposition protest since an Islamist-led government took office, reflecting mounting tensions over unemployment and other social woes. The protest was organised by trade unions which accuse PM Abdelilah Benkirane of failing to deliver on the pledges of social justice that brought his party to power in the wake of the Arab Spring. "There are more than 50,000 people who are demonstrating to call on the government to start a genuine dialogue addressing our country's social ills," opposition Socialist MP Hassan Tariq said.

A official estimated the crowds at between 15,000 and 20,000.

"The trade unions are united and the message to the Benkirane government is clear: he needs to change his strategy," Tariq told AFP as the crowd marched through the heart of Morocco's largest city and its economic capital.

Union leaders have been appealing to the government for talks on improving salaries and social conditions in a country where almost half of people aged between 15 and 29 are neither working nor in school, according to a World Bank report this month.

The report said Morocco's large youth population -- 30 percent of the total of 32 million people -- could be an "engine of growth" but that young people faced numerous obstacles.

Morocco's government is grappling with a crisis caused by drought and a sharp slide in tourism revenues, the country's largest source of income along with transfers by Moroccans abroad and phosphate exports.

Hundreds of youths from the February 20 Movement -- known as M20 -- also turned out in Casablanca for the demonstration on Sunday.