MEXICO CITY — Three men were being held as possible suspects in the fatal grenade attack this week on an Independence Day celebration in the western state of Michoacan, authorities said Thursday.
Two were detained in northern Zacatecas state late Wednesday after being hospitalized with injuries from a car crash. The third, who had been in the same crash but was released from the hospital, was arrested Thursday afternoon in Zacatecas.
The men are being held by the Mexican army, which is leading the campaign against drug traffickers.
Authorities said they were investigating whether a Michoacan-based drug gang known as La Familia was involved in the twin grenade attacks Monday in Morelia, the Michoacan state capital. Seven people died and more than 100 were hurt. Officials previously blamed organized crime but they did not specify a group.
An additional suspect was arrested in Michoacan, news media reported. But state officials confirmed only the Zacatecas arrests and provided few details. The federal attorney general's office, which is in charge of the investigation, did not comment on the arrests.
News reports said the men arrested in Zacatecas appeared to bear injuries similar to shrapnel wounds suffered by victims of the grenade attack.
A spokeswoman in the attorney general's office confirmed that investigators were looking into whether La Familia was behind the attack. A text message purportedly sent out by the group a day earlier denied involvement.
The message steered blame toward the Zetas, a brutal gang that got its start as the armed wing of the so-called Gulf cartel. La Familia and the Zetas were considered allies; the message, if authentic, might suggest a split.
The attackers' motives remained unclear. Some analysts believe the violence against civilians may have been an attempt to pressure President Felipe Calderon, a native of Morelia, into abandoning his nearly 2-year-old crackdown on organized crime. The president is from Michoacan.
Bystanders have been killed in the crossfire during the crackdown, but civilians uninvolved in the drug wars were not directly targeted before Monday's attack.
In other developments, Mexican officials announced late Thursday that soldiers had seized $26.2 million believed to belong to a Sinaloa trafficking group. The money, in 809 packets of U.S.dollars, was discovered Sunday during a raid of a house in Culiacan, the capital of Sinaloa state.
Documents found there suggested the money belonged to a trafficking group allegedly run by Ismael Zambada, known as El Mayo, federal officials said in a statement. It was one of the largest cash seizures since Calderon launched his crackdown.
Cecilia Sanchez of The Times' Mexico City Bureau contributed to this report.
Mexico under siege
For previous coverage of Mexico's drug war, go to latimes.com/siege.