Neighbors described two or three loud explosions shortly after 3:30 Thursday morning. The blasts damaged two cars at a home on Melannie Court in San Jose.
One of the neighbors who called 911 spoke to ABC7, but was afraid to appear on camera.
"There was two loud explosions and right away I woke up because my kids started screaming," she said.
Several explosive devices were found by investigators outside of a home.
Police confirmed the targeted home is where the leader of the /*Mongols Motorcycle Club*/ Santa Clara chapter lives.
A member of the Mongols is a suspect in the murder earlier this month of /*Mark Guardado*/. Guardado was the leader of the /*Hell's Angels*/ San Francisco chapter. The memorial service held Monday in Daly City attracted more than 1,000 bikers.
There is an immediate concern of an escalating war.
"I just hard the Hell's Angels leader got killed and hearing this the Mongols might be involved is, I'm just thinking it's retaliation, which is a close call because it's someone's home," Kassandra Jones said.
Police are concerned but said they are not assuming Thursday's incident and Guardado's murder are connected.
"We just don't want people to think we are just looking at this one particular group we just leave it open so it could been any suspects that could have done something like this," Officer Jermaine Thomas said.
San Jose police are working with several other agencies in hopes of identifying a suspect.