Millions of Moroccans are heading to the polls to vote on the constitutional reforms that King Mohammed VI says will bring democratic reform to his country.

The Interior Ministry reported that turnout was about 60 percent of the 13 million registered voters just before the polls closed. Preliminary results are expected after polls close Friday evening.

King Mohammed announced his proposed reforms last month. The referendum would limit his power while strengthening parliament and the prime minister's office.

But the country's youth-based pro-democracy movement has criticized the proposed changes for not meeting what they called “demands for a true separation of powers.”

Critics say the new constitution still keeps King Mohammed firmly in power by allowing him to choose the prime minister from the party that won the elections and continue to oversee the country's religious matters, security apparatus and judiciary.

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

In Washington Friday, a State Department spokesman said the United States welcomed the peaceful

referendum during a period of “profound change for Morocco.”

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

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