Sheila Coleman, of the campaign, said: "People are coming from all over to be here today and it is really lovely that they want to pay their respects."
Members of the campaign were afterwards joining thousands of others at the memorial service inside Anfield.
A minute's silence was being held at 3.06pm - the time when Liverpool's illfated 1989 FA Cup semi-final against Nottingham Forest on Saturday, April 15, 1989 was halted after officials realised fans were being crushed on the terraces.
This service was also being attended by up to 500 members of the victims' families along with representatives of Liverpool Football Club and a choir from St Francis Xavier school.
Trevor Hicks, who lost his daughters Sarah, 19, and Victoria, 15, in the tragedy, was making his final speech as chairman of the Hillsborough Family Support Group. He steps down at midnight tonight.
Phil Hammond, 55, from Liverpool, whose son Philip junior died in the tragedy, will replace him.
A candle was being lit in memory of each victim and each name read out, with the anthem You'll Never Walk Alone concluding the service.
At the interdenominational, open service, Father Desmond Powell, Rev Julie Fleming and Rev Derek Bibb were lead-ing the prayers.
The service was begining at 2.45pm.