Federal prosecutors in El Salvador say four National Civil Police officers and 15 soldiers participated in death squads that killed 36 people.

Prosecutor Walter Ruiz said Wednesday that arrest warrants were issued for the government agents and nearly three dozen civilians who allegedly participated in the killings. The suspects also allegedly robbed banks.

The killings occurred between 2014 and 2016. Some victims were alleged gang members while other killings appeared to be contract hits.

National Civil Police Director Howard Cotto says the squads began killing gang members, but branched out to make money.

The Defense Ministry says four of the suspected soldiers are no longer in the service.

El Salvador experienced a homicide rate of more than 100 killings per 100,000 residents in 2015 before seeing some improvement last year.