Updated at 6:21 p.m. ET

Five people are dead and at least three others were “gravely” wounded in a shooting at the Capital Gazette newspaper in Annapolis, Md., officials announced at a news conference Thursday afternoon.

Acting Anne Arundel County Police Chief William Krampf confirmed an adult male suspect is in custody and being interrogated by law enforcement.

Krampf described the weapon used by the gunman as a “long gun” and said officials recovered “what we thought may have been an explosive device that has been taken care of.”

It is unclear whether it was an explosive device.

County Executive Steven Schuh told CNN four of the victims’ bodies were found on the floor of the newsroom and a fifth person — a woman with severe wounds to her upper body — died after being evacuated to the University of Maryland’s Shock Trauma Center.

Two or three other wounded people “with less severe injuries” are being treated at Anne Arundel Medical Center, Schuh said.

It is unclear whether the shooting was limited to the newsroom or the gunman attacked people on other floors.

Capital Gazette reporter Phil Davis shared details on Twitter, writing: “Gunman shot through the glass door to the office and opened fire on multiple employees.”

Gunman shot through the glass door to the office and opened fire on multiple employees. Can’t say much more and don’t want to declare anyone dead, but it’s bad.

— Phil Davis (@PhilDavis_CG) June 28, 2018

Anthony Messenger, an intern for the newspaper, first tweeted about the shooting at 2:43 p.m. ET, writing, “Active shooter 888 Bestgate please help us.”

Active shooter 888 Bestgate please help us

— Anthony Messenger (@amesscapgaz) June 28, 2018

Anne Arundel County Police spokesman Lt. Ryan Frashure confirmed that authorities arrived on the scene within 60 seconds of receiving a call about the shooting.

Annapolis Mayor Gavin Buckley praised law enforcement for its response, saying that if officers “were not there as quickly as they were it could have been a lot worse.”

The newspaper’s website lists 20 newsroom employees.

#update confirming active shooter at 888 Bestgate Road in Annapolis. Building evacuated. Officers continuing to search building. Relocation point is inside Lord and Taylor in the mall.

— Anne Arundel Police (@AACOPD) June 28, 2018

Frashure said during the news conference that law enforcement from Annapolis, nearby Howard County, the Maryland State Police and federal agencies were participating in the response.

He said authorities were focused on clearing the building and reuniting the people inside with their families. Families should go to the Lord & Taylor outlet at the nearby Annapolis Mall, he said.

Gov. Larry Hogan tweeted he was “absolutely devastated to learn of this tragedy,” adding that he is in contact with authorities on the scene.

Absolutely devastated to learn of this tragedy in Annapolis. I am in contact with County Executive Steve Schuh, and @MDSP is on the scene assisting @AACOPD. Please, heed all warnings and stay away from the area. Praying for those at the scene and for our community. https://t.co/bI6PdUjHfh

— Governor Larry Hogan (@GovLarryHogan) June 28, 2018

President Trump also tweeted about the incident, saying he had been “briefed on the shooting at Capital Gazette,” and he offered “thoughts and prayers.”

This is a breaking news story. As often happens in situations like these, some information reported early may turn out to be inaccurate. We’ll move quickly to correct the record and we’ll only point to the best information we have at the time.

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