The FBI is offering a $20,000 reward for information about an attack on a U.S. consulate in western Mexico.

Two hand grenades were lobbed at the consulate in Guadalajara, in the western state of Jalisco, just before 11 p.m. Friday, according to a statement from the U.S. Embassy in Mexico City. The FBI was working with Mexican counterparts to find the person or group responsible for the attack.

Just three days after the attack, on Monday, six state policemen were killed about 150 miles away in a rural part of Jalsico. The state attorney general said in a statement that the officers were killed as they were transporting a prisoner. The state is the home base of the Jalisco New Generation drug cartel.