Spain said Monday it was in talks with Morocco on the fate of a Spanish pedophile who had his pardon revoked after it sparked angry protests in the north African country.

King Mohamed VI of Morocco on Sunday revoked a pardon granted to Daniel Galvan Vina, who was convicted of raping 11 children aged between four and 15 and sentenced in September 2011 to 30 years in prison in Morocco.

Hundreds of activists took to the streets of Morocco's main cities late on Saturday to protest against corruption, the high cost of living and other causes of discontent, according to AFP reporters and witnesses.

Rights groups, trade unionists and the February 20 protest movement had called the demonstrations, amid frustration at the perceived failure of the Islamist-led government to make good on its electoral promises.

Syria declared Morocco's ambassador persona non grata on Monday, the foreign ministry said, in a tit-for-tat move hours after Rabat expelled Damascus's envoy to the North African country.

"Syria has just considered the accredited Moroccan ambassador to Syria persona non grata," ministry spokesman Jihad Makdissi said via Twitter, after Morocco demanded that Syrian ambassador Nabih Ismail depart the country.

Rabat has condemned an alleged plot to bomb the U.S. Capitol over which a Moroccan suspect was arrested, the official MAP agency reported Monday.

The Federal Bureau of Investigation on Friday arrested Amine el-Khalifi, a 29-year-old immigrant from Morocco living illegally in the U.S. state of Virginia, in a sting operation.

Morocco's moderate Islamist party won a parliamentary election for the first time, preliminary results showed Saturday, the latest religious party to achieve huge gains on the back of the Arab Spring.

The victory by the Justice and Development Party (PJD) comes just one month after Islamists won Tunisia's post-revolution election and days before their predicted surge in Egyptian polls.