A 26-year-old man remains in custody after he was arrested on suspicion of the murder of 84-year-old Louisa Denby, who he is related to, and the attempted murder of a nine-year-old boy who was stabbed in a skate park, police said.
A second 26-year-old man was also arrested in connection with Mrs Denby's murder, while three men aged 18, 24 and 29 were held on suspicion of attempted murder over the incident in the skate park.
All four have been released without charge, police said.
More top news
A soaking then sunshine this weekend
As Hungary prepares to vote in a referendum on the EU's resettlement of refugees, thousands of migrants remain in limbo on the border.
The promotional video features a 'Game of Thrones' soundtrack and a range of landmarks but fails to show parts of the city destroyed by war.