Istanbul police have detained a total of six people as part of an operation to "ensure public order", police said on Friday.Teams from Istanbul police department's Public Security Branch Office and homicide department launched simultaneous operations, which was supported by police helicopters, at 13 addresses in the city's Sultangazi, Eyüp and Güngoren districts.Police seized four firearms including two rifles and a Kalashnikov, plus a large amount of ammunition and drugs.On Thursday, police detained 44 suspects in a drug trafficking operation in Istanbul.