Waco, Texas (CNN) Texas law enforcement officials are investigating what they say are new threats against officers from biker gangs in the wake of a recent shootout in Waco.

Members of the Bandidos biker gang who are in the military "are supplying the gang with grenades and C4 explosives," according to a bulletin issued Thursday by the Texas Department of Public Safety and reviewed by CNN.

The bulletin warns of plots targeting high-ranking law enforcement officials and their families with car bombs. The bulletin is based on unsubstantiated information from an informant who claimed to have obtained it from Bandidos and Black Widows motorcycle gang members.

The Bandidos want to retaliate against police for shooting "their brothers" as they came out of the Twin Peaks restaurant, the bulletin says.

The gang has ordered a hit against Texas troopers and other officers, according to the bulletin. Among the threats are running over officers at traffic stops and the use of grenades and Molotov cocktails and firearms.

The bulletin includes some locations as possible targets: McLennan County Jail in Waco as well as sites in Austin, El Paso, Dallas, Corpus Christi and Houston.

The Texas Department of Public Safety didn't immediately respond to CNN's request for comment.

On Sunday, nine bikers were killed during a shootout at a Twin Peaks restaurant in Waco. Police Sgt. W. Patrick Swanton said Wednesday that three or four Waco officers probably opened fire but that it's too early to tell how many of the dead bikers may have been struck by police bullets.

Swanton told CNN's "Erin Burnett OutFront" after the bulletin was sent to authorities that police live with constant threats.

"Unfortunately, in our line of work, it's something we deal with day in and day out. I would, however, like to say this, to those that are listening that are making the threats: The incident that occurred here Sunday afternoon ... was an absolute tragedy," he said. "However, those of you that were there know that we did absolutely nothing to start that. We would ask you to remember that and remind you that although you have totally different ways from us, law enforcement did not start the melee."

He wouldn't discuss what changes or precautions his department was taking.

More trouble?

Sheriff Ira Mercer of Palo Pinto County told CNN that he is still planning to have extra officers in Mingus even though a planned motorcycle club rally is reportedly canceled.

Mercer said he talked with officials from Waco and McLennan County.

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"They are of the strong belief that trouble is not over with," he said. "We have other intel that other bikers groups might be coming here to show us they can."

As a precaution, he was getting an extra 30 law enforcement officers from outside agencies to set up a blockade on the roadway to the rally's planned site beginning Friday, when the four-day event was scheduled to begin.

On Thursday, he hosted a law enforcement intelligence meeting with 70 members of federal, state, and local agencies over the possible rally.

The event was planned by the Cossacks motorcycle club, which lost seven members in the fight.

Hundreds of weapons

Police are finding more evidence and clues about what happened.

Among them: More than 300 weapons left behind. And some bikers may have stashed away even more, police said.

"These were vicious criminals that knew that they were in trouble, and they were trying to dispose of evidence," Swanton said.

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With 170 suspects in custody, authorities have a complex investigation on their hands. All the suspects face charges of engaging in organized crime, and each one has bail set at $1 million.

So far, only one person has made bail. Jeff Battey, 40, bonded out of the McLennan County jail on Wednesday, a law enforcement source with knowledge of the investigation said.

How it all started

Swanton said some motorcycle groups had reserved the outdoor bar area at Twin Peaks when "an additional biker gang" showed up uninvited.

A quarrel in the parking lot soon followed, Swanton said, and it may have involved a tiff over a parking spot or someone having his foot run over.

A waitress who was there told CNN that it appeared to be a "simple fist fight."

The woman, who didn't want her name disclosed or her face shown out of safety fears, said almost all the bikers were on the patio outside.

"There was a little bit of yelling. Like you couldn't hear exactly what they were saying," the woman said. "Next thing you know you hear the first gunshot go off. ... There was a lot of screaming (inside the restaurant)."

The arrest warrants for some suspects offered more details: Members of the Cossacks were in the Twin Peaks parking lot when members of the rival Bandidos biker gang arrived.

Photos: Multiple deaths in shootout between biker gangs Photos: Multiple deaths in shootout between biker gangs People in Waco, Texas, stand near the parking lot of a Twin Peaks restaurant where nine people were killed in a shooting on Sunday, May 17. At least 18 people were hospitalized as well after a melee between rival biker gangs. Hide Caption 1 of 10 Photos: Multiple deaths in shootout between biker gangs Emergency responders tend to a wounded person near the restaurant. Hide Caption 2 of 10 Photos: Multiple deaths in shootout between biker gangs People stand near the restaurant as police investigate the scene. Hide Caption 3 of 10 Photos: Multiple deaths in shootout between biker gangs Emergency vehicles and members of law enforcement gather near the scene of the shooting. Hide Caption 4 of 10 Photos: Multiple deaths in shootout between biker gangs Authorities block an access road as the investigation takes place. Hide Caption 5 of 10 Photos: Multiple deaths in shootout between biker gangs Waco police posted this photo to its Facebook page, warning the public to stay clear of the area. Hide Caption 6 of 10 Photos: Multiple deaths in shootout between biker gangs Bikers wait in a line as law enforcement officers investigate the shooting. Hide Caption 7 of 10 Photos: Multiple deaths in shootout between biker gangs Bikers wait on a hill near the parking lot of the restaurant. Hide Caption 8 of 10 Photos: Multiple deaths in shootout between biker gangs A McLennan County deputy stands guard near a group of bikers. Hide Caption 9 of 10 Photos: Multiple deaths in shootout between biker gangs A law enforcement officer walks past debris near the parking lot of the restaurant. Hide Caption 10 of 10

But the ruckus didn't stop there. Swanton said there were "crime scenes inside and outside" the restaurant, including in the bathroom, dining area and around the bar.

The assailants used all sorts of weapons -- brass knuckles, guns, knives and chains. And when police responded, Swanton said, some bikers turned their weapons on them.

The waitress said she and other Twin Peaks workers hid in a refrigerator for 10 to 15 minutes.

Restaurant security camera footage showing Sunday's events is now in the hands of investigators, a representative for the Waco Twin Peaks said Wednesday. The video shows that "no violence started inside the restaurant," the franchise said.

"What happened inside the restaurant was that people sought safety inside, where they assisted each other and came to the aid of patrons, staff and management," the statement said.

Waco police initially estimated that investigators recovered more than 1,000 weapons from the restaurant. Police revised that number Wednesday afternoon, saying their count had reached 318 weapons, including more than 100 handguns and more than 100 knives.

Who was involved?

The nine men killed in the shootout ranged in age from 27 to 65, the Southwestern Institute of Forensic Sciences said. Some of them were fathers. All of them died of gunshot wounds.

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Families went through harrowing hours when they tried to find their loved ones and weren't sure whether they'd survived, said Rocki Hughes, whose ex-husband, Jacob Lee Rhyne, was among those killed.

"We didn't find out and it wasn't confirmed until my kids had already seen pictures of their dad dead on the tailgate of a truck," she said. They recognized him, she said, because of his large beard and the tattoos of his children's names on his forearms.

Rhyne, 39, had been a member of the Cossacks for about six months. He went to the restaurant to make peace with the Bandidos, Hughes said.

Portraying all the bikers as violent, she said, simply isn't fair.

"He didn't believe in guns," she said. "He got in many fights throughout his years, but he never needed a gun to protect himself."

So why did he join the Cossacks?

"To be a part of something, I guess," Hughes said. "That's a question I'm still asking. ... Our kids are broken up. He was an awesome father, and just as good as a friend, and I don't understand it either."

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Sandra Lynch, aka "Drama," was among those arrested. A member of the Los Pirados motorcycle club, she's married to Michael Lynch, who also was arrested.

They're grandparents who share a love for biking -- and Twin Peaks.

Their son told CNN they're not criminals or gang members. They were at the restaurant for a monthly meeting, nothing more.

"Everyone there is not a thug. My parents are not thugs," he said. "I think this is injustice to have so many people in jail." He would not give his name, saying he feared police retribution.

None of the defendants has had their day in court yet. Some of their families, reached by CNN, say the high bail is ridiculous and unfair.