Union County is launching a homicide task force to solve unsolved murders, but the county's largest city is not taking part.

The unit is made up of 16 officers from Hillside, Plainfield, Linden, Scotch Plains and Union Township, as well as the county prosecutor's office and county police department. Five assistant prosecutors also are members. No officers from Elizabeth are included in the unit.

The unit was formally launched Thursday by Union County Prosecutor Theodore Romankow. The county prosecutor is fed up with what he calls Elizabeth's refusal to acknowledge and deal with gang activity.

"There is a serious problem in Elizabeth, and I think Elizabeth is ignoring it," Romankow says.

Elizabeth Mayor Christian Bollwage doesn't believe his city is to blame for the unsolved murder rates. Bollwage says the prosecutor's office is already in charge of homicides, and they "should look in the mirror before accusing other agencies of high unsolved homicide rates."

More than 57 percent of Elizabeth's murders are unsolved.

AP wires contributed to this article.