Shooters opened fire on a holiday party in San Bernardino, California, killing 14 people and wounding 17.
The attacker, identified as Enes Omeragic, opened fire with an automatic weapon at a betting shop.
The rampage took place at the central bus station in the southern Israeli city of Beersheba.
A gunman opened fire at Umpqua Community College in Oregon earlier on Thursday.
The school is in lockdown and the suspect is at large, officials confirmed.
A police official identified the gunman as Kevin Downing, a man in his late 60s from Fort Lee, New Jersey, according to media reports.
Tremaine Wilbourn faces first-degree murder charges for allegedly killing Officer Sean Bolton on Saturday.
The man was "just firing into the air" at a busy intersection.
Officials say the gunman, who is thought to be a defendant, has been apprehended.
This story is developing and will be updated as more information becomes available.
Police who responded to the scene after receiving calls about a shooting could still hear gunfire when they arrived.
Sydney's city center was on lockdown after a gunman took hostages in a cafe in the financial district