An urgent manhunt is under way after a father abducted three boys from their foster home in south London, the Met Police said.
Detectives are looking for Imran Safi, 26, who is said to have threatened the foster carer with a knife in Coulsdon last Thursday.
He is accused of taking Bilal, Mohammed Ebrar and Mohammed Yaseen - aged six, five and three.
Eight people have been arrested in connection with the abduction.
All eight people, aged between 17 and 37, were arrested in Croydon and have been bailed to a later date, the Met Police said.
More than 100 officers are currently working to locate the three brothers and an image of Mr Safi has been distributed to all UK ports.
Image copyright Met Police Image caption Imran Safi is said to be in possession of a knife, the Met saidMet Police Commander Jon Savell said it was "an absolute priority" to find the three children.
"They have been taken from a place of safety and we are growing increasingly concerned about their wellbeing, particularly as we remain in the midst of a global health crisis.
"While we do not believe at this time there is any immediate risk to their physical safety, their location, access to accommodation, healthcare, and other provisions is entirely unknown. We are concerned about the longer-term impact of this on all three children.
"An intense investigation into how this abduction was planned and carried out is being led by detectives in south London, alongside a manhunt being led by specialist detectives within the Met."