U.S. President Barack Obama and other Americans are observing a moment of silence Friday morning for the victims of a mass shooting, a week ago, in Newtown, Connecticut.

Twenty-six people were killed, last Friday, after 20-year-old Adam Lanza opened fire at an elementary school he is believed to have attended. Twenty of the victims were children.

Investigators believe Lanza killed his mother before driving to the school, where he also took his own life. Authorities are trying to determine a motive.

The mass shooting has renewed U.S. debate on gun control and gun violence. On Thursday, a U.S. federal gun violence task force, formed in response to the shootings, met for the first time.

Vice President Joe Biden told the group the Obama administration was determined to find solutions that include input from the mental health and education communities as well as from legal experts addressing the constitutional right of U.S. citizens to bear arms .

Mr. Obama, on Wednesday, had called for Congress to reinstate an assault weapons ban that lapsed in 2004.

Meanwhile, the powerful National Rifle Association — the largest gun rights organization in the U.S. — is set to hold a Friday news conference. On Tuesday, the group said its members were “shocked” by the Connecticut shootings but wanted to give the families of victims more time to mourn before making additional statements.

Funerals resume on Friday for the victims. At least two adults and two children who attended the school will be laid to rest.