Police say at least two shootings took place in Newark Saturday night and Sunday morning leaving four people dead and one in critical condition.

Authorities say Natasha Aeriel, 19, her brother Terrance along with Ofemi Hightower and Deshawn Harvey were gunned down execution-style in a park behind Mt. Vernon Elementary School Saturday night. Natasha Aeriel is in fair condition. The three others died.

Police are looking to the public for answers and trying to piece all of the information together.

Three out of the four shot behind the school were Delaware State University students, police say.

Less than a mile away on another street, another young man was shot Sunday morning. The man has not been identified, but detectives believe the killing might be related to a shooting earlier in the night on the same street.

Newark residents say they are fed up with the level of crime.

Some criticized Newark Mayor Cory Booker for not speaking out publicly about the shootings. A spokesperson from the mayor?s office told News 12 New Jersey that Booker personally called the families and offered his condolences.

Community groups are reportedly planning a protest in front of City Hall Monday calling on Booker?s administration to do more about the violence level.

AP wire reports contributed to this article.