Oakland Fire Department crews have been battling a slew of fires around the city this morning, some of which may have been intentionally set.

In total, crews responded to blazes at three separate sites. The largest was a 5-alarm fire that erupted at a condo complex currently under construction on West Grand Avenue and Filbert Street. It was first reported just after 2 a.m., according to ABC7. All six structures on site caught fire, and four of the buildings have been deemed "total losses" by firefighters.

The housing complex, called the Ice House, was slated to sell townhomes priced at around $600,000 and was scheduled to open to residents in December. The CEO of the development firm, City Ventures, told ABC7 that construction will continue on a portion of the site that was unaffected by the blaze. However, about 50-75 construction jobs will now be lost due to the fire. 

According to reports, the complex was equipped with security cameras and guards were on site. The San Francisco Field Division of the federal Bureau of Alcohol, Tobacco, Firearms and Explosives is investigating the fire.

Embers from the five-alarm fire at the complex reportedly started a separate fire at a home nearby on Isabella Street and Grand Avenue. Roughly 30 people were evacuated from nearby homes, and PG&E cut power to nearly 2,000 homes as firefighters battled the blaze.

800 Block of Isabella- Crews quickly extinguish #basementfire #oakland pic.twitter.com/qqYZZGG7Dp

— Oakland Firefighters (@OaklandFireLive) October 23, 2018

Fire crews also responded to a spot fire at another construction site on Peralta and 32nd streets this morning. According to KTVU, its causes are also being deemed suspicious, as firefighters have said that windows were broken and gas had been poured into the building. 

So far, one injury has been reported in connection with these blazes. One firefighter reportedly hurt their leg while responding to the Ice House fire and has been transported to a hospital in stable condition.

At a press conference this morning, Mayor Libby Schaaf stated that it's too soon to tell whether the fire at the Ice House complex was set intentionally, KTVU adds.

"We do not know if this fire was caused by an arsonist," Schaaf said. "But we do know that arsonists have been trying to burn down housing projects in Oakland."

In the last two years, there have been a series of fires at housing sites under construction that were caused by arson and remain unsolved. This summer, an Oakland lobbying group comprised of businesses and developers announced a $300,000 reward for information leading to the conviction of those involved, according to the San Francisco Chronicle. 

While motives for the arson are unclear, some city officials suspect that it may stem from those opposed to gentrification. 

At a Tuesday morning news conference, Oakland Fire Department Deputy Chief Nick Luby told reporters that it was too early in the investigation to determine the cause of this morning's fires.