Salvadoran police with some of the 77 people detained Thursday in what authorities called the dismantling of a network that managed the finances of the leaders of the Mara Salvatrucha (MS-13) gang. (ERICKA CHAVEZ/EPA) (Ericka Chavez/EPA)

The raids began before dawn. A thousand police fanned out across El Salvador’s wrinkled landscape, busting down doors at used-car lots, intercepting cross-country buses and surprising customers at a drive-in motel called the Three Aces. Authorities seized dozens of businesses, claiming they belonged to the Mara Salvatrucha, the country’s largest gang.

In an extensive operation Thursday that resulted in 77 arrests, 106 seized vehicles and 34 frozen bank accounts, the Salvadoran government targeted the financial holdings of the gang, exposing the enrichment of its leaders and sending a message to the impoverished rank and file. “You should know that your leaders are living differently from the rest of you,” said Douglas Meléndez, the attorney general.

Among those captured in Operation Check was Marvin Ramos Quintanilla, an evangelical pastor who authorities say was leading a double life, working as the gang’s treasurer and using his religious credentials to enter prisons and coordinate homicides, extortion and money-laundering operations with gang members.

This country of 6.3 million people has the highest murder rate in the hemisphere because of the bloody feuding between its gangs and the security forces.

The financial activity of El Salvador’s three main gangs, the Mara Salvatrucha, also known as MS-13, and two factions of Barrio 18, has long been murky. Reliable information is scarce. In the past, governments have tried to weaken the gangs — which have about 70,000 members in El Salvador but extend well beyond its borders — by cracking down in the streets and in the prisons.

In February, authorities in Honduras dealt the first major blow to Mara Salvatrucha’s finances, ordering the arrest of 15 national leaders, confiscating more than $1 million in cash, freezing 137 bank accounts, and seizing luxury houses, cars and businesses allegedly run by the gang. Thursday’s operation in El Salvador signals a similar strategic shift.

“This is the first effort to follow the money,” said Alex Segovia, an economist and onetime adviser to former president Mauricio Funes, who left office in 2014. “With this investigation, the government has recognized that the gang is a criminal business with the potential to accumulate capital.”

Salvadoran investigators focused first on the income that Mara Salvatrucha gets through extortion, and then turned to a network of businesses allegedly used to launder the money: used-car dealerships, drive-in motels, brothels, two major urban bus companies, dozens of pirated taxis, restaurants, bars, and a fruit and vegetable stand. Some of the accused have business connections in the United States, where the Mara Salvatrucha has a strong presence in Los Angeles and Washington, D.C. The gang is also involved in small-scale drug and weapons trafficking, authorities said.

According to the attorney general, the targeted Salvadoran businesses are run by a small group of gang leaders called the Federation, who in recent years have withdrawn from direct involvement in traditional criminal activity and devoted themselves instead to managing the gang’s finances. “While the rest of gang members are getting killed and getting locked up, their leaders are living in fancy houses, driving luxury vehicles and sending their kids to private schools,” Meléndez said.

“MS-13 members should know that their leaders aren’t being honest with them,” he said.

El Salvador’s police director and its security minister repeated this message during a packed news conference Thursday, featuring a PowerPoint presentation with diagrams of the gang’s hierarchy and its modus operandi.MS-13, the authorities said, consists of 249 local “cliques,” encompassing an ascending order of roles: collaborator, observer, member or “homeboy,” clique-leader, program-leader, and top leader (known as “ranflero”).

Some analysts said the authorities were emphasizing the difference in income between gang leaders and their followers in an effort to sow dissension.

That strategy may not be effective. “When it comes to organized crime, there’s a misguided belief on the part of authorities that by cutting off the monster’s head, the problem will be solved,” said José Miguel Cruz, a political scientist. “But when you take out the leaders, you create space for others” to take their place. Police captured five top MS-13 leaders in Operation Check this week; several others may have left the country with $600,000 the authorities had been tracking.

Politicians and the public applauded the apparent step forward in the authorities’ investigations, though it will fall to the courts to determine whether the evidence — including thousands of pages of bank activity — supports the accusations. There is concern among human rights groups that the police have cast too wide a net.

One of those arrested, Dany Romero, is accused of passing information to gang members in prison through his work for a nonprofit organization. He was released from prison in 2006 and since then has worked with violence prevention and human rights groups. Over the past two years, as violence has increased between El Salvador’s gangs and its security forces, Romero has tracked and denounced police shootings of unarmed gang members.

“This is retaliation from the government for my work telling the world about the extrajudicial assassinations of gang members,” he said from the back of a pickup truck, where he and seven other men were handcuffed, sweating profusely under the mid-day sun on Thursday.

Though Operation Check is a new line of investigation into the gangs, the news was presented in traditional fashion. In the parking lot of a San Salvador convention center, scores of masked police officers milled about the booty they had seized: 25 colorfully painted school buses, more than 70 trucks and cars, a commercial water tank truck and 77 people in handcuffs in the backs of trucks.

“Today was a show,” Cruz said. “Tomorrow we’ll see if the case is well-documented.”