The Gottis are back in town — and the bloodshed could just be beginning.

Police are taking a serious look at whether Gambino crime family boss Francesco “Franky Boy” Cali was whacked in an internal war for control — with one of John Gotti’s brothers and a key associate fresh out of prison and possibly looking to seize power, law enforcement sources told The Post on Thursday.

While the motive for the Wednesday hit on Cali outside his Staten Island home remains under investigation, cops were probing whether it was part of a brewing American-vs.-Sicilian power struggle — with Gene Gotti looking to claw back control for the red, white and blue faction of the syndicate from Cali, the son of Sicilians with close ties to his homeland, sources say.

If so, “there’s going to be an all-out war,” one source said.

“The Sicilians are not going to sit back and let that happen.”

Gene Gotti, 72, was released from federal prison in September 2018 after 29 years behind bars for heroin dealing.

A month earlier, Gotti associate John Carneglia, 74, was released from the slammer after serving time for the same rap.

Carneglia was reputedly the one who fatally shot then-Gambino boss Paul Castellano when a team of gunmen ambushed him outside Sparks Steak House in Midtown in 1985 — on the orders of Gene’s older brother, John Gotti, who would then take over the family.

And investigators say there are real similarities between this week’s rubout — which saw a gunman open fire on Cali outside his Todt Hill home — and Castellano’s slaying.

“It’s in his bloodline,” one source said of Gene Gotti. “This is very similar in some ways to what happened to Paul Castellano in front of Sparks Steak House.”

But there’s also a big difference with the Cali hit.

“This was in front of his family, in his house. You don’t usually see this. There were other places this could’ve happened,” retired Chief of Detectives Robert Boyce said at the scene Thursday.

Boyce said that he believed it was a hit within the Gambino family but that it was “early” to tie it to Gene, as he hasn’t been out of prison long.

John Gotti, Gene’s notorious brother, took over the Gambinos after Castellano’s slaying and ruled with a swagger while avoiding prosecution until he was finally put away in 1992.

That year, the feds hit the Teflon Don with racketeering, murder and conspiracy charges that stuck, thanks to Gotti’s right-hand man, Salvatore “Sammy the Bull” Gravano, who agreed to testify against him.

“The Teflon is gone,” James Fox, the head of the FBI in New York, said after Gotti’s conviction. “The don is covered with Velcro, and all the charges stuck.’’

John Gotti died in prison in 2002 — not at the hands of an assassin but from cancer — and was succeeded as godfather by another brother, Peter.

When Peter was put away for a lengthy stint a few years later, the Sicilian faction of the family wrested back control, first in the hands of Domenico Cefalu, then Cali in 2015

Gene was a mob captain when he was locked up — and he allegedly ran a loan-sharking operation while behind bars — so he is still entitled to a role in the Gambinos, sources previously told The Post.

Sources said on Thursday that there has been speculation that Gene might have been expecting more clout once he got out.

Cali — who married into the powerful Sicilian Inzerillo Mafia clan — had reportedly been bringing over wiseguys from the Italian island to bolster the family’s ranks because he thought they were less likely

to flip for law enforcement, sources said.

With his murder, law enforcement is on the lookout to see “if another body drops,” a source said.

If somebody does get killed, it will almost certainly be from the side behind the hit, sources say.

And if Gotti’s side was indeed behind the bloodshed, there may be other evidence.

Sources say they will likely have done practice runs to nail down the route and assess the scene before the actual slaying, and it could be caught on surveillance footage.

Gene Gotti could not be reached for comment.

Additional reporting by Kevin Sheehan, Ruth Brown and Ben Feuerherd