More than 2000 people gathered at Sydney's St Mary's Cathedral on Friday evening to pray after the Easter Sunday bombings in hotels and churches which killed 253 people and wounded about 500.

During the mass of remembrance Sydney Archbishop Anthony Fisher called for an end to hatred and violence while remembering the two Australians killed in the attack, Manik Suriyaaratchi and her 10-year-old daughter Alexendria.

He told the crowd it was "clear" the Easter Sunday bombers "hated Christians".

Australia's Foreign Minister Marise Payne, Immigration Minister David Coleman and deputy Labor leader Tanya Plibersek joined the gathering on Friday evening.

It was followed by a candlelight vigil in the cathedral forecourt where people huddled together, some holding Sri Lankan flags and many using their phones as lights.

Sri Lanka's Consul General Lal Raj Wickrematunga told the crowd the attack was one of Sri Lanka's "worst days" but the community will get through with compassion and love.

Among those gathered was Shanoi Fernando who grew up just 15 kilometres away from St Sebastian's Church in Negombo which was bombed in the attack.

Mr Fernando, who lives in Chatswood in Sydney's lower north shore, said his mother-in-law still lives in the area and was at a different church the same time of the bombings.

"These events have tried to break us down, but tonight, this proves we will come together," he told AAP.

Prime Minister Scott Morrison on Friday confirmed a Sri Lanka-based Islamic terrorist organisation was responsible for the Easter Sunday bombings.

Australian Associated Press