A quiet Iowa community has been left reeling after seven people were killed, including two students, in what police believe was a domestic violence-fueled rampage.

The bloodshed unfolded across several locations on Monday in Muscatine, close to the Illinois border, with the victims believed to have been relatives of 52-year-old Ryan Willis McFarland, who also took his own life.

Investigators say the suspect carried out the shootings before turning the gun on himself as officers closed in on him near the city's riverfront trail.

The violence sent shockwaves through the close-knit Iowa community, with Muscatine Community School District later saying, 'our hearts are broken by this unimaginable loss,' after revealing that two of the victims were students and two others were employees.

Police were first called to the 200 block of Park Avenue shortly after 12.15pm on Monday following reports of gunfire.

When officers arrived, they discovered four people with gunshot wounds. All of them were pronounced dead at the scene.

As the investigation expanded, two additional bodies were found at separate locations in the city. 

One man was discovered dead in his home and the other was inside a business, he said. 

Authorities believe the violence was connected to a domestic dispute.

'While talking to Ryan Willis McFarland, he took his own life,' Muscatine Police Chief Anthony Kies said.

'Today I simply do not have the words,' said Kies. 'This act of evil and what it has done to our community.'

Authorities have yet to release the names of the victims and any details about them.

The school district announced that counselors and support services would be available beginning on Tuesday morning at Muscatine High School, Susan Clark Junior High, Madison Elementary, McKinley Elementary and Franklin Elementary.

'Our hearts are broken for the family members, friends, colleagues, classmates, and all those affected by this unimaginable loss. We ask that you keep everyone impacted in your thoughts during this incredibly difficult time,' Superintendent Clint Christopher said.

'We encourage anyone who needs support to take advantage of these resources and to check in with one another. The strength of our district has always been found in the care and compassion we show each other during difficult times.'  

Local politicians also expressed their condolences to everyone affected by the killings.

'We don't know a lot, but we know enough to recognize that this is a tragedy of massive proportions,' wrote State Senator Janice Weiner. 'My heart goes out to the entire Muscatine community - holding them in my thoughts and prayers.

'This tragedy impacts everyone - community, schools, a sense of safety. And community will be needed now more than ever. I hope all who need it will reach out for support.'

Similar thoughts were echoed by Nick Salazar, a Muscatine native and longtime community advocate running for Iowa House District 96. 

'My heart is heavy as our community processes the tragic events that unfolded today in Muscatine,' Salazar wrote. 'My thoughts are with all those affected by this tragedy. Families, neighbors, and first responders.

'Right now, we come together as a community to support one another, check on our loved ones, and keep the victims and their families in our prayers.

'Muscatine is a strong community. We will stand together through this difficult time.'

The city's police department is continuing to investigate the shootings. Officers have asked anyone with information to contact the major crimes unit.

Kies confirmed that McFarland had a criminal record, but wouldn't share any further details.

If you or someone you know is experiencing a mental health crisis, help is available. Call 988 for confidential and free support. Online services are available here.