Up to 25,000 people have taken part in a memorial service for the 96 Liverpool football fans killed in the Hillsborough disaster 20 years ago.
The supporters were crushed to death on 15 April 1989 during Liverpool's FA Cup semi-final tie with Nottingham Forest at the stadium in Sheffield.
Families, survivors and players were at Anfield for the service.
Culture Secretary Andy Burnham was heckled by those angry that no-one has been held to account for the tragedy.
More than 20,000 fans are at Anfield to pay their respects to the 96 victims
As Mr Burnham, the Secretary for Culture, Media and Sport spoke, he was forced to pause as the crowd broke into song with "Justice for the 96".
He added: "Those who died will forever leave their mark on this city and this country."
Before the service started, the Kop and the Centenary stands were opened early and then part of the main stand was opened to the public.
As victims' families took their places on the Kop, the crowds gave them a huge round of applause and standing ovation.
Liverpool goalkeeper Pepe Reina led the first team out to huge cheers and applause, followed by the team's manager Rafa Benitez, coach Sammy Lee and players Jamie Carragher and Steven Gerrard.
There were also cheers and applause for Everton's manager, David Moyes, with huge chants around the stadium for Kenny Dalglish.
Rebecca Kelly, BBC News
Anfield was filled with 25,000 fans chanting Kenny Dalglish's name, greeting him with a rapturous applause, and then a silent grief took over the stadium as the Hillsborough death toll was read out.
A mother, two sisters, a brother and a cousin are just some of the 96 names that were read out as candles were lit for each victim.
The city's rival fans, Liverpool and Everton supporters, stood side by side, arms around each other as they marked the 20th anniversary of the sport's greatest tragedy.
The stands were awash with red and blue banners and unrestrained tears from all those in the ground.
One woman stood apart from the crowds, wearing the historic grey Liverpool strip from 1989. She was wearing a Santa hat and carrying a sign with Justice pinned to her back, looking lost.
Men were looking at their feet, trying to comprehend what had happened, women were hugging their children as they listened to the harrowing details of what happened 20 years ago.
The service started at 1445 BST and a two-minute silence was held at 1506 BST, the exact time the game was abandoned two decades ago.
At the end of the silence, church bells from around Liverpool could be heard ringing out 96 times.
Thousands also stopped in Liverpool city centre to observe the silence.
Sue Joyce, 43, from West Derby, Liverpool, said: "We've come here today to show the victims and the families of those who died that we have not forgotten what they have suffered.
"It may be 20 years since the disaster took place but those that were there will always be in the thoughts of every Liverpool fan around the world."
The Bishop of Liverpool, the Rt Rev James Jones, opened the service.
"For many here today it seems still like yesterday. Those we lost always in our minds," he said.
"Never a day passes without a thought of what their tomorrow might have been, without that longing for justice for their sake as well as for ours."
Dalglish, who was Liverpool's manager when the disaster took place, read a passage from the Bible, Lamentations of Jeremiah.
Margaret Aspinall, vice-chairwoman of the Hillsborough Families Support Group, gave the second reading.
Members of the crowd interrupted Sport Minister Andy Burnham's speech
Liverpool players Carragher and Gerrard presented Freedom Scrolls to Mr Hicks and a representative of each of the families.
Meanwhile the first team were given a standing ovation and a rendition of "Liverpool we love you" for their performance against Chelsea in the Champions League tie on Tuesday night. The players had worn black armbands to remember the club's dead fans.
The service concluded with Gerry Marsden leading the crowd in a rendition of You'll Never Walk Alone, as 96 red balloons were released into the sky.
Thousands of Liverpool scarves of past and present team strips were held high as fans swayed and cried while singing the club's anthem.
One man stood out in the Kop's crowd holding high a framed photograph, presumed to be of a loved one killed at Hillsborough.
Meanwhile about 2,000 Liverpool and Forest fans gathered in Nottingham's Old Market Square to remember those who died.
On the day of the tragedy, Liverpool supporters were in the Leppings Lane end of the ground.
South Yorkshire Police, which oversaw the event, opened a large exit gate and many Liverpool fans went on to the terrace. This left the fans inside trapped between people entering the ground and the metal fences at the front of the stand.
The families of the victims have kept up a campaign to have the events which led to the deaths fully investigated, despite previous inquiries.
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