A man has been arrested on suspicion of the murder of nine-year-old Lillia Valutyte.
Lillia was stabbed to death in Fountain Lane, Boston, Lincolnshire, on the evening of Thursday, 28 July.
Lincolnshire Police said a 22-year-old man was arrested in the Boston Central Park area at around 2.45pm today, 30 July. It comes after police released CCTV images of a man they wanted to find.
A spokesperson said: "The arrest follows a combination of intelligence and information supplied by several members of the public. We’d like to thank everyone for their assistance as we continue our investigation.
"We are not looking for anyone else in connection with this incident. There will continue to be a significant police presence in the town while our investigation progresses."
The force said two people who were arrested earlier this week have now been released with no further action.
There has been widespread outrage over Lillia's death, which reportedly happened as she played with her younger sister on the street just yards from an office where their mother was working at the time.
Home Secretary Priti Patel said she was "appalled" at the incident.
She tweeted: "I am appalled to hear of the tragic death of a nine-year old girl in Boston, Lincolnshire. My heartfelt sympathies go out to her family. "The police have my full support to conduct a thorough investigation and it is important we allow them the space to do so."
Flags are flying at half-mast around Boston. Paul Skinner, leader of the town's borough council, said Boston was "united in mourning".
The town's mayor, Anne Dorrian, said she was "deeply saddened".
She said: "I just cannot begin to imagine the pain and anguish they will be experiencing right now following this despicable crime, and it’s something that no parent or grandparent should ever have to encounter. I also extend my sincere condolences to her young friends and classmates too."
Jurate Matulioniene, a family friend and chairwoman of the Boston Lithuanian Community, described Lillia as "a beautiful angel" who loved dancing.
She told The Times: "Lillia was a beautiful angel, she was quite quiet and loved dancing.
"The family used to come to all of our community events and they would always stay late to help clear up."
Meanwhile, people have been arriving at St Botolph's Church, also known as Boston Stump, to light candles in Lillia's memory.
In a statement the church said: "Every life is precious, but the loss of a child is particularly difficult for us to comprehend. We cannot begin to imagine the pain the parents, family and all those who have been affected by this tragic loss are feeling.
"We stand in this space alongside our community as a place where we can bring our thoughts, feelings and emotions – whatever they are. This ancient church is a visible sign of the God who is there with us, in the very depths of our pain and bewilderment."
Members of Boston's Lithuanian community said they were raising money in Lillia's memory. The Boston Lithuanian Community Facebook page said money would "support Lillia's family in their devastating moment".
Writing on the social media site, Lynda Wiggins said: "Heartbreaking, how could anyone do this to an innocent little girl?"
Jadey Simper added: "She’s a child. Just can’t believe this, just horrible. When will this stop? She's a baby still. Poor, innocent little girl. My heart breaks."