Thousands of pro-democracy demonstrators marched through Moroccan cities Sunday to protest constitutional changes they say fail to ease King Mohammed VI's autocratic grip on power.

At least 1,000 people marched in the capital, Rabat. Thousands more rallied in Morocco's main economic hub, Casablanca, where the Associated Press reports that pro-government supporters clashed with demonstrators.

There were also pro-democracy protests in the port city of Tangiers and the popular tourist destination of Marrakech.

The February 20 Movement, whose protests over the past few months prompted the king to initiate the reforms, denounced his new constitution as “window dressing” meant to preserve the monarchy's authority. It said the charter's overwhelming approval in Friday's national referendum was a sham.

Under the proposals, the prime minister would no longer be appointed by the king, but would be selected by the majority party in parliament and designated as “president of the government.” The charter broadens the powers of the country's elected politicians and grants the judiciary more independence.

But critics say the reforms fail to create a modern constitutional monarchy, leaving the king as the head of state with absolute control over the military, the security apparatus and all religious matters.

It also allows him to dissolve parliament, though not unilaterally.

Moroccan officials say 98 percent of Friday's voters approved the new constitution, with a stunning 72 percent of the country's 13 million registered voters casting a ballot.

The United States, European Union, France and Spain have welcomed the referendum in Morocco, which has strong ties to the West.

King Mohammed announced the proposed reforms last month in a bid to introduce greater political openness.

In February, pro-democracy demonstrations swept across Morocco like much of North Africa and the Middle East. But the effect of the so-called “Arab Spring” has been somewhat muted in Morocco compared to the protests that toppled rulers in Tunisia and Egypt.

Morocco's reform movement has been driven by a loosely organized collection of youth-led groups that have called for reform – not revolution – with few seeking an end to the monarchy.

The 47-year-old Mohammed took over the Arab world's longest-serving dynasty in 1999. He currently holds virtually all power in the majority Muslim country and is its top religious authority.