The attacker opened fire at a US business park.
Three people have been killed and two injured following a shooting at a drugstore distribution centre in Harford County, Maryland on Tuesday afternoon.
Roughly 1,000 people work at the Rite Aid support facility, but the area is now believed to be secure.
"The distribution centre is where products are received and processed for delivery," Rite Aid spokeswoman Susan Henderson said.
"This is part of a large facility that is a distribution centre. The shooting happened adjacent to the primary building."
https://twitter.com/Harford_Sheriff/status/1042773302501167104?ref_src=twsrc%5Etfw
It is believed the gunman opened fire around 9am Eastern Time (2pm GMT).
The distribution centre is located outside the City of Perryman, roughly 30 miles northeast of Baltimore.
"We are closely monitoring the horrific shooting," Gov. Larry Hogan tweeted. "Our prayers are with all those impacted, including our first responders. The State stands ready to offer any support."
Maryland Governor Larry Hogan called it a "horrific shooting."
https://twitter.com/GovLarryHogan/status/1042779107891798021
The attack comes almost three months after an attacker killed five people in a newspaper office in Annapolis, Maryland.
