Britain's King Charles and British Prime Minister Keir Starmer have paid tribute to the spirit of unity shown in the aftermath of the 7 July bombings in London, 20 years on from the attacks.
On 7 July, 2005, four homegrown Islamist extremists detonated suicide bombs across London at Aldgate Station, Edgware Road, King's Cross and Tavistock Square, killing 52 people and injuring hundreds more.
The city is holding several events to mark the anniversary, with members of the royal family expected to join those directly affected at commemorations.
The king urged people to draw on the "extraordinary courage and compassion" shown following the attack.
"We remember with profound sadness the 52 innocent people who were killed in senseless acts of evil -- and the enduring grief of their loved ones," he said in a statement.
"In doing so, we should also remember the countless stories of extraordinary courage and compassion that emerged from the darkness of that day.
"The selfless bravery of our emergency services, transport workers, and fellow citizens who rushed towards danger to help strangers reminds us of the very best of humanity in the face of the very worst."
The king asked for the country to reaffirm its commitment to building a society of all faiths and backgrounds, standing against those who seek to divide.
Mr Starmer echoed this sentiment.
"Those who tried to divide us failed," he said in a statement.
"We stood together then, and we stand together now - against hate and for the values that define us of freedom, democracy and the rule of law.
"We honour the courage shown that day -- the bravery of the emergency services, the strength of survivors, and the unity of Londoners in the face of terror."
The Duke and Duchess of Edinburgh will attend a National Service of Commemoration at St Paul's Cathedral and survivors and the families of the victims will hold a service at the memorial to them in Hyde Park, which will be attended by the Prince of Wales.
King Charles said that "while the horrors will never be forgotten", the country "may take comfort from the way such events rally communities together".
"It is this spirit of unity that has helped London, and our nation, to heal," he said.
Speaking ahead of the anniversary, UK interior minister Yvette Cooper warned that Islamist and right-wing extremism remained the country's most significant threats.
