A package exploded and left a staff member with minor injuries Tuesday evening, officials said.

The explosion occurred around 7:18 p.m. at 39 Leon St. near Holmes Hall, Boston Police Department Superintendent Felipe Colon said at a press conference Sept. 13. 

Northeastern University Police Department, or NUPD, Chief Michael Davis said the campus is secure and that NUPD officers responded to the explosion within one minute. 

Another suspicious package was located when officers responded, Colon said, and was “rendered safe.”

“A search revealed a second similar package that was ultimately rendered safe by our bomb squad. I will tell you that the scene is secure and that the investigation is ongoing,” Colon said at the press conference. 

The 45-year-old male staff member who opened the package sustained “minor” hand injuries, Colon said. According to Boston Emergency Medical Services he was transported to a nearby hospital. 

Wednesday morning, Provost David Madigan and Chancellor Kenneth Henderson sent out a message to the university community highlighting available resources. 

“Events such as the incident that took place on our Boston campus last night can create or heighten anxiety for many of us,” the email reads. “We would like to underscore what was communicated to our community last night: Multiple law enforcement agencies have determined that the campus is safe and secure. Classes, research, and all other campus activities have resumed today.”

Residential Life will have a presence in residence halls today, will have open office hours and are “available to engage in conversations with students and provide support,” the email reads. 

Northeastern also offers confidential counseling for students and staff, Henderson and Madigan wrote. Students can call University Health and Counseling Services at 617-373-2772 or access Find@Northeastern, the 24/7 mental health support service, by calling 877-233-9477 if they are in the United States. 

The email also said support is available from the Center for Spirituality, Dialogue and Service at 617-373-2728 and from the We Care team at [email protected] or 617-373-4384.  

As for faculty and staff, the email said they can contact the Employee Assistance Program at 800-624-5544.

Announcements from the university regarding the incident can be found online. 

“The safety and security of our campus community is essential and remains our highest priority,” the email read. “We will continue to provide continuous updates as new information becomes available.”

Northeastern sent out its fifth NU Alert of Tuesday night around 11:30 p.m. and said campus will be open tomorrow and no students were injured.

“NUPD is increasing patrols and security across the campus. At this time, we expect the campus to be open and fully operational tomorrow,” the alert read. “The safety and well-being of our community is always our most important priority. We will update you as more information becomes available.”

At the press conference, Boston Mayor Michelle Wu thanked first responders for the “very swift, coordinated and effective” response. 

“As a mom, I just sent my own two little babies back to school in our Boston Public Schools. I take very seriously that this city is home to everyone’s young people, from our littlest learners up to our college students and university staff,” Wu said. “We want to make sure to emphasize that this is of the utmost priority — the safety and well-being of all of our young people here.”

Davis thanked all of the responding agencies, which include Boston Police Department, FBI Boston division, Boston Fire Department and Boston EMS, according to various speakers at the press conference.

“It’s very important to note that our campus is secure, and we will maintain a secure campus in perpetuity,” Davis said. “That is our work and that is what we will continue to do, and we will be working with our partners here to get that result.”

Jason Cromartie, assistant special agent in charge of FBI Boston, said the agency is offering its full support including resources from the Joint Terrorism Task Force, the Evidence Response Team and special agent bomb technicians. 

Boston Police Commissioner Michael Cox said if people see something suspicious they should “say something.”

Police and other authorities were unable to answer further questions, citing the ongoing investigation.

Earlier Tuesday night, Northeastern canceled classes in nearby buildings for the evening through an NU Alert sent around 8:40 p.m.

“Evening classes in Behrakis, Shillman, Ryder, Kariotis, Dockser, and West F are canceled due to the ongoing investigation in the area,” read a second NU Alert. 

In an email statement to The News at 8:55 p.m., Northeastern University spokesperson Shannon Nargi said the package was “delivered to Holmes Hall,” and the building was evacuated.

Holmes Hall is located between Lake and Meserve Halls and across the street from Willis Hall. 

This is a developing situation and The News will provide updates as information becomes available. This story was last updated at 12:25 p.m. Sept. 14.