Marchers carried signs and chanted, "The people want to overthrow tyranny, The people want to overthrow corruption," the Los Angeles Times reported Monday.
Unlike in the recent past, no riot police showed up.
"These protests are taking place today at the same time the [Moroccan regime is] launching a campaign of unprecedented defamation and disinformation against the movement," a blogger wrote. "The demonstrators are marching now to Parliament … no intervention by police, who merely regulate the marchers."
Moroccan officials appeared to be taking a milder stance dealing with protesters than in recent weeks when police in riot gear allegedly beat demonstrators with batons, the report said.
Observers said the lack of action by authorities could be an attempt to limit broadening support for activists in mounting an "Arab Spring" uprising similar to those in Tunisia and Egypt.
Anti-government demonstrators said online the lack of violence by riot police shouldn't be confused with a lack of repression.
Protesters in Casablanco and Rabat carried posters of Kamal Amari, who died Thursday from wounds he suffered during clashes with police on May 29 in Safi, about 200 miles south of Rabat.
"Martyr rest, will continue fighting," the demonstrators chanted.