Washington , Reuters, 6 Dec. 2015 – U.S. investigators are increasingly convinced the San Bernardino shooters may have been planning more attacks, given the quantity of weapons in their possession, a senior U.S. government source said on Sunday.

Investigators were still uncertain about possible targets that may have been identified by Tashfeen Malik, 29, and her U.S.-born husband, Syed Rizwan Farook, 28, the source said. The couple killed 14 people and injured 21 on Wednesday when they opened fire on a gathering of public employees in Southern California.

The source also said investigators do not believe Enrique Marquez, the man suspected of providing weapons to the couple, is linked to terrorism but are still investigating.