Militia groups are once again on the rise in the United States, up almost 40 percent in 2015.

The Southern Poverty Law Center tracks the numbers and hate-related incidents around the country. It identified 276 militia groups in the latest count, up from 202 in 2014.

The center says the number represents a renewal of growth after several years of declines.

The movement grew rapidly after President Obama was elected, from 42 groups in 2008 to a peak of 334 in 2011.

Ryan Lenz, a spokesman for the Southern Povery Law Center, told Eyewitness News there are several things that stand out in the case in southwestern Kansas, where three men were arrested for threatening an attack on an apartment complex and mosque in Garden City. Lenz said the bomb they were planning to build uses the same ingredients that Timothy McVeigh used in the Oklahoma City Bombing in 1995.

Lenz said militias are growing in numbers again, as well as Muslim hate crimes, driven by immigration fears and the political climate.

"It's really interesting the case in Kansas," Lenz said. "It really is the perfect storm of all these factors that have driven growth in the movement. What stands out to me is the ultimate racism at the core of their motives."

Lenz also points out that not all militias, or their splinter groups, are dangerous or commit hate crimes. He also said the number could grow again, depending on the outcome of the election in November.