The dismembered remains of a woman were found by police in the Alexander River, north of Netanya, on Friday, sparking fears that the discovery could be linked to the mutilated remains of another woman found in a garbage can in Ramat Gan on Wednesday.
On Thursday, a passer-by walking along the river spotted a human leg floating in the water.
Fearing the leg could be linked to the human remains found in Ramat Gan, police launched a large-scale search of the stream.
Police and Zaka divers, backed by ground-based search teams walking along the banks of the stream, and a police helicopter hovering above, converged on the site on Friday morning.
The divers found more body parts, and eventually recovered the remains of a woman's body from the water.
A special investigations team has been set up by Tel Aviv Police to handle the recovery of the body parts.
Meanwhile, the Lahav 433 special police unit has been tasked with leading the investigation on the national level, and to oversee the forensic identification process.
A court-imposed media ban has been placed on all forensic findings from the body parts found in Ramat Gan and the Alexander stream.
Speaking from the scene of the grisly discovery on Friday, Tel Aviv Police chief Cmdr. Shahar Ayalon called for members of the public to "report missing persons." Police have not received reports on missing women in recent weeks.
Police Insp.-Gen. David Cohen arrived on the scene and called for calm, saying it was too early to know whether a serial killer was behind the murders.
"We have turned our full attention and made available all the resources needed to investigate the acts of cruel murder and violence which have occurred in recent days," Cohen said on Saturday night.
"We are looking at a series of incidents which have different circumstances and backgrounds. Police are working day and night in extended shifts to beef up our presence, while our investigators are working long hours."
Also on Friday morning, the body of a man in handcuffs was discovered in an empty structure not far from Beit Dagan, near Rishon Lezion.
The Central Unit of the police's Central District has been tasked with leading that investigation, on which a media ban has also been imposed.