By Steve Tawa

PHILADELPHIA (CBS) — The City of Philadelphia once again took a leading role in the observance of the nation’s holiday honoring Dr. Martin Luther King, with a ceremonial ringing of the iconic Liberty Bell.

Inside the Liberty Bell Center, across from Independence Hall, local and national dignitaries huddled around the Liberty Bell at noon today.

Each year, the Philadelphia MLK Association for Nonviolence chooses bell ringers to symbolically tap the bell, and similar ceremonies take place in other locations around the US.

This year’s honorees are two daughters of Malcom X and Betty Shabazz.

“Malaak Shabazz, current co-chair of the United Nations Subcommittee on Racism, and her sister, Ilyasah Shabazz, a leading advocate of youth education and leadership development,” said William Tucker, chairman of the Philadelphia MLK Association.

The national bell-ringing ceremony began in 1986, the year the first national King Holiday was observed. It was requested by Dr. King’s widow, Coretta Scott King.

During his remarks, Mayor Nutter alluded to violent flashpoints in Philadelphia that have been making headlines recently.

“We must be a more peaceful city, a more loving city, and a less violent city,” the mayor said.