Houses searched over Abdullah Deghayes's Syria death
Several houses have been raided by police investigating the death in Syria of a teenager from Brighton.
Abdullah Deghayes's father said his son, 18, "died in battle" after going with two brothers to "join the fight" against President Bashar al-Assad.
Four addresses in Brighton and Hove, including the Deghayes's home, were searched by Sussex Police and the South East Counter Terrorist Unit.
Material was taken for examination but no arrests were expected, police said.
Abdullah left for Syria in January without his parents' consent.
After the raid, his father Abubaker said: "Police rang the bell and then tried to force the door open. My sister-in-law opened the door, but I was asleep.
"I was shaken and woken up by police telling me that they have a court order to search the house, not to move and to stand up while they searched my pyjamas.
"They told me if I didn't co-operate I would be handcuffed."
In April, Mr Deghayes said he had heard of his son's death via Facebook.
"He was killed in a battle, as far as I know," he said.
It was said at the time he had died at some point in the previous few weeks, apparently killed fighting with a militant group linked to Al-Qaeda against President Assad's forces.
When his death was announced it was thought his brothers Jaffar, 16, and Amer, 20, were still in Syria, having gone there with an aid convoy in October.
Mr Deghayes said Amer had suffered a bullet wound to the stomach in the battle but Jaffar was unhurt.
"I am sad for the loss of Abdullah, but at the same time, I can feel some comfort as he went for a just cause," he said.
"I hope he's in peace. Neither Abdullah or his brothers are terrorists."
Their mother Einas Abulsayen said her dead son was a "very naive, very helpful, brave boy".
The teenager was the nephew of Omar Deghayes, who was held by the US at the Guantanamo Bay camp as an enemy combatant following his arrest in Pakistan, in 2002.
'No immediate threat'
Sussex Police said the searches of the houses were being carried out by unarmed officers, with search warrants issued by magistrates under the Terrorism Act 2000.
Ch Supt Nev Kemp said: "This is a necessary part of our continuing work to safeguard communities locally and nationally, including those who have links to Syria.
"We understand what a distressing time this is for the family and we do not want to cause further distress to them.
"I can give local people an assurance that this is not in response to any immediate threat to local communities and anyone who does have any concerns can contact our local officers for further reassurance."