Two men set fire Wednesday night to two vehicles owned by environmental activist Carroll Cox at his Mililani home.

Police have opened a second-degree arson case after two parked cars were found ablaze outside Cox’s home at about 10:50 p.m. Wednesday, said Honolulu Police Department spokeswoman Teresa Bell.

She said two unknown males went into the driveway, set two vehicles ablaze and fled the scene.

Honolulu firefighters estimated damage at $3,000.

Cox said he went outside after hearing a "god-awful boom," then a door slamming and a vehicle squealing its tires.

He extinguished the two fires with a fire extinguisher and found flares on the windshields of the two vehicles. He said an accelerant was apparently used.

Security cameras, which captured the arson, also showed the suspects driving past Cox’s house before the fire, apparently to turn around in the cul-de-sac for a quicker getaway.

"These guys were really cool, calm and collected," Cox said. "They were very cocksure of themselves."

He said the fire could have jumped to his house.

"This was reckless disregard for human life," he said.

Cox said the fire may be related a May 6 attack near Boxer Road in Kalaeloa when a masked man struck him on the head with what appeared to be a pipe and another masked man stole his car keys. Nine staples were required to close the wound.

At the time, Cox was in his car photographing a modular house on Hawaiian Home Lands property that did not have a permit for use, Cox said. He said Mark Aiwohi, of trucking business Aiwohi Bros., gained access to the land and put the trailer there through a handshake deal with a DHHL land agent.

According to DHHL, Aiwohi had planned to seek a permit for the modular home, and it was put there temporarily.

Cox’s friend George Grace III said Thursday that Aiwohi had threatened him in May if he didn’t get Cox to back off his investigation into DHHL.

Grace, who operates Kalaeloa Raceway Park, got a temporary restraining order against Aiwohi for the threat, which allegedly happened at Grace’s business a day after Cox was beaten.

Aiwohi did not respond to attempts to reach him for comment. He has previously denied threatening Grace or having any part in Cox’s beating.

Cox says he reported the questionable actions of the state agent to DHHL in April but that nothing has been done.

Cox said he is not worried about his safety, but more frustrated with the way the state has handled his complaints about violations on Hawaiian homelands.

"We have a government entity, the DHHL, and this is serving as a breeding ground for this kind of nonsense," he said. "I’m being terrorized because these people have safe harbor at the Hawaiian Home Lands and yet the government is rooting others out with lesser violations. And these people are known substantial violators, and nothing happens."

He suspects the same people are involved in both attacks because correcting the violations would cost them money, and he never had problems with other people for bringing up issues.

"It would have cost people substantial money if it was done right, and DHHL did absolutely nothing and basically encouraged it," he said. "Many of the complaints that I filed with information that I submitted to DHHL, it fell on deaf ears."

DHHL said they forwarded Cox’s complaints about the DHHL agent to the attorney general’s office to avoid any appearance of preferential treatment. A spokeswoman for the attorney general’s office did not immediately respond to a request for a comment Thursday afternoon.

Grace said a group of Cox’s friends raised a $5,000 cash reward for any information leading to the arrest of Cox’s attackers in May or the arson suspects.

"Whoever the person is that’s bringing this harm to him, they should be stopped," Grace said.