Two men arrested over the murder of a two-year-old girl who was found dead in a pool of her own blood were released without charge today.
A third man, aged 21, remains under arrest on suspicion of the murder of the toddler, who was named locally as Casey Leigh Mullen.
A West Yorkshire Police spokesman said the 21-year-old has also now been arrested for an offence of serious sexual assault in connection with the incident.
A post-mortem examination was completed in the early hours of this morning, but the results are being withheld for operational reasons, a West Yorkshire Police spokesman said.
The force spokesman said forensic examinations were taking place at two addresses in the Leeds area.
A Leeds City Council spokesman confirmed that social services were briefly involved with the family following an incident in 2005.
Neighbour Kieran Jackson, 23, who lives two doors away and has a two-year-old son, said: "They were just like any normal happy family. They are just a lovely family.
"We are all shocked but we all pulled together last night and most of the neighbours got together for a cup of tea.
"It's sickening, isn't it? It knocks you out. Nothing like this has ever happened around here before.
"This is the best street in the estate."
Bunches of flowers and teddy bears were left outside the three-bedroom council home in Oak Tree Crescent, Gipton, where a red plastic bus could still be seen in the front garden.
One message read: "Missing you so much already, you will always be in my heart. Love you millions, Aunty Zoe."
One card, attached to a bouquet of flowers, read: "Casey XX. A little smiler, up with the angels. RIP. From all at 14."
Another read: "A little angel, rest in peace. Lots of love, Angela, Molly, Peter, Aaron."
The force's homicide and major inquiry team, led by Detective Superintendent Steve Payne, is investigating the death.
Keith Beaumont, 58, said all the neighbours were pulling together.
Describing the events of Sunday night, he said: "There was a lot of commotion going on, and a lot of shouting. There were lads banging at the window, shouting and carrying on.
"The police and paramedics came and there was an ambulance.
"They brought the baby out and she was looking very ill."
He said he had talked to Sarah Pringle, who lives next door to the murdered girl and who tried to resuscitate her.
He said: "She did her very best. She tried to revive the little girl.
"She ran up the stairs, found the baby, and tried to give her mouth-to-mouth resuscitation."
He said Ms Pringle, who has a four-year-old daughter of her own, was good friends with Casey's family and had been to his house last night.
He said she was "absolutely distraught".
Speaking of Casey, he said: "She was a lovely little girl. She was an angel, always smiling and waving over. She will be very sadly missed.
"It's absolutely horrendous. We've never seen anything like this in the area."
The secretary of the residents' association, Terry Beaumont, brother of Keith, said nothing like this had ever happened before in the local area. He said it was "just unbelievable".
He said the mother, named locally as Samantha Canham, 21, lived with her partner and two children - the little girl and a three-year-old boy.
He said: "They were a lovely family, it's just a shock for everybody."
He said nobody knew where Ms Canham was but she had contacted Ms Pringle yesterday and was totally distraught.
He had spoken to Ms Pringle and she told him what happened on Sunday.
He said: "She went round for a cup of tea and the mother found the baby wasn't breathing and she brought her down. Sarah tried to give the girl the kiss of life. She is completely distraught."