Lakeport police investigators are looking into reports of "acid bombs" being set off during the past two weeks in the area of Clearlake Avenue and North High Street.
The devices, which incorporate a mixture of chemicals combined in plastic soda bottle, are similar to those used in two incidents in 2012, police said.
When combined, the chemicals create enough pressure to cause the plastic bottles to explode. The explosion often sounds like a gunshot, officials said.
Police said that in January 2012, an acid bomb exploded in the 2000 block of Hartley Street. Another was set off by juveniles in July 2012 in the 900 block of Bevins Court.
Police said chemical or acid bombs are dangerous and can cause serious injury such as physical trauma, respiratory problems and chemical burns. Residents who encounter acid bombs should stay clear of them and immediately notify 911 for police and fire, officials said.
Any one with information regarding recent acid bomb explosions is encouraged to contact the Lakeport Police Department.