In a significant blow against the powerful Sinaloa drug cartel, Mexican troops on Thursday killed one of the group’s top figures during an arrest raid in western Mexico.

The raid came as troops in Tijuana rounded up dozens of police officers in a separate operation targeting organized crime.

Ignacio Coronel Villarreal is described as one of the three most important bosses in the cartel, which is based in Sinaloa state and run by the country’s most-wanted drug suspect, Joaquin “Chapo” Guzman. Coronel, known as “Nacho” and in his mid-50s, was highly sought by U.S. and Mexican authorities.

Authorities said Coronel headed the group’s operations in the western states of Colima, Nayarit and Jalisco, where troops tracked him down Thursday. U.S. officials have described him as a pioneer in making large quantities of methamphetamine to be smuggled into the United States.

Army officials said Coronel was slain after opening fire on troops closing in on him in an upscale, tree-lined suburb of Guadalajara, long considered a haven for drug bosses. Coronel kept two residences that he used as safe houses and maintained a low profile, the army said.

A soldier was killed and another was injured, Gen. Edgar Luis Villegas said during a brief news conference. He said troops arrested a close aide of Coronel.

Coronel’s death represents a victory for President Felipe Calderon’s nearly 4-year-old war against drug cartels. Calderon has dispatched nearly 50,000 troops into the streets, but the country’s soaring violence has frightened many Mexicans.

The raid should help Calderon fend off allegations that the government offensive has left largely unscathed the Sinaloa group while hitting its rivals. Calderon has vehemently denied that accusation.

Coronel is the second suspected drug kingpin slain by troops in the last year. In December, commandos killed Arturo Beltran Leyva, a former Guzman ally, during a raid in the city of Cuernavaca.

Beltran Leyva’s death has spawned a bloody succession struggle inside the organization he headed. Coronel’s foot soldiers battled with remnants of that group in Jalisco in recent months.

Though for years a close associate of Guzman, Coronel was considered by U.S. and Mexican authorities a potent trafficker in his own right, with direct access to cocaine supplies in Colombia. Coronel was considered especially adept at importing into Mexico the chemical ingredients for making methamphetamine.

The FBI, which offered a $5-million reward for his capture, had said Coronel’s group “has been growing in power since the 1990s and is now considered one of the most powerful drug-trafficking organizations in Mexico.” He is named in federal drug-trafficking indictments in Texas and New York.

Mexican authorities offered their own reward equal to about $2.5 million.

In Tijuana, the military rounded up 56 members of various law enforcement agencies in one of the largest efforts in recent years to purge corrupt police in the border city of Tijuana.

Forty officers from the Tijuana police department and 16 agents from the Baja California attorney general’s office were detained. Six former officers were also arrested, authorities said.

Gen. Alfonso Duarte Mugica, who runs military operations in Tijuana, said the sweep targeted law enforcement officers tied to the Arellano Felix drug cartel, which has long used police as bodyguards and informants.

The arrested officers were taken to a military air base and paraded in front of the news media, at which point some proclaimed their innocence.

The sweep marked the latest push by authorities to keep the pressure on organized crime groups in northern Baja California. Unlike other regions in Mexico with spiraling drug war violence, authorities there have been credited with lowering crime rates and arresting organized crime bosses.

The anti-corruption measures, headed by Julian Leyzaola, Tijuana’s secretary of public security, have been a key component of the strategy. Since he assumed the post 2 1/2 years ago, more than 460 law enforcement personnel have been arrested or fired or have left the department.

The scale of Thursday’s operation was a sign that corruption persists, but that authorities seem committed to rooting out bad officers, according to experts and law enforcement officials in the U.S. and Mexico.

“How many police chiefs would arrest 40 guys from his department, and do it again and again and again?” said one U.S. law enforcement official who spoke on condition of anonymity because he is not authorized to speak to the news media.

Evidence of high-level corruption was revealed last week when U.S. authorities arrested the top liaison officer of the Baja California attorney general’s office, Jesus Quinones Marques, who was accused of passing along confidential information from U.S. law enforcement officials to cartel leaders.

Meanwhile, the U.S. government has shut indefinitely its consulate in Ciudad Juarez, a border city racked by drug violence, to evaluate security conditions. The U.S. Embassy in Mexico City said in a statement Thursday that the consulate would “remain closed until the security review is completed.”

The consulate closed briefly in March after three people connected to the consulate were killed by suspected drug cartel hit men.

ken.ellingwood@latimes.com

richard.marosi@latimes.com

Ellingwood reported from Mexico City and Marosi from San Diego. Times wire services were used in compiling this report.