(CNN) -- Mexican authorities on Monday were still investigating who was responsible for a car bomb found in Ciudad Juarez and later disarmed with a controlled explosion by federal police.
The car bomb was located during the overnight hours Friday near an industrial park after police received an emergency call saying someone had been executed, according to a bulletin released by federal police. A second car with a body in it was also located at the scene.
The call was believed to be a luring tactic to bring authorities to the scene where the car bomb was planted, a federal police spokesman said.
"We used a controlled explosion to neutralize the threat," federal police spokesman Ramon Salinas said.
Local reports said Tovex, a water gel explosive often used in mining, was located inside the car. The material also was used in a fatal car bomb attack by a drug gang in Juarez in July.
"The investigation is no longer in our hands. We were the first responders, but now the investigation is in the hands of the attorney general's office," Salinas said of the latest incident.
On Monday, the Chihuahua attorney general's office did not answer repeated calls by CNN inquiring about information into the investigation.
In April, after federal police took over security in Juarez from the Mexican military, ambush-style attacks against the police increased. More than two dozen attacks have occurred against the federal police since April, according to Salinas.
Juarez is Mexico's most violent city, averaging eight to 11 murders a day in 2010, federal police said.