Around 500 people were also injured in the blasts.
Bombers targeted a number of locations across the country's capital city of Colombo, including three churches in Kochchikade, Negombo and Batticaloa - which were attacked during Easter services - along with the Shangri-La, Cinnamon Grand and Kingsbury hotels.
The seventh attack hit a hotel in the suburb of Dehiwala in the south of Colombo, while police confirmed the eighth blast was a suicide bomb.
Aussie Manik Suriaaratchi and her 10-year-old daughter Alexendria were killed when the Negombo church bomb was detonated.
Australian Prime Minister Scott Morrison said: "We deeply regret these deaths and we extend our deepest and most sincere sympathies to the family," he said.
"As the days pass and the injured are treated and some of them succumb to their wounds, we are seeing this massacre go from what was bad, very bad, to much, much worse."
Manik's husband was uninjured in the blast as he was parking the family car when it exploded.
The country's finance minister, Mangala Samaraweera, claimed the bombings were an attempt to drag Sri Lanka back into a civil war.
He called the attacks 'a diabolic attempt to create racial and religious tensions in this country yet again, thereby pulling the country backwards just as we as a country - economically, socially and otherwise - are recovering from the protracted war which destroyed the fabric of our nation for nearly 30 years'.
Sri Lankan police have arrested 24 people in connection to the attacks but it is not yet clear as to who was behind them.
At a press conference yesterday evening, Prime Minister Ranil Wickremesinghe said the focus was on finding the people who committed the atrocities.
He said: "We must look into why adequate precautions were not taken. Neither I nor the Ministers were kept informed.
"For now the priority is to apprehend the attackers."
Police have arrested 24 people. Credit: PA
At the time of the attacks, President Maithripala Sirisena issued a statement calling for people to remain calm, urging them to support the authorities in their investigations.
The statement, which was posted on Facebook, roughly translates as: "The President says that he will expect all the people's support during the explosions in this situation. The President says that he will fulfil the responsibility of all the people in this regard.
"In the country, the people who are in the background of a sad incident are the ones who are saving the peace of the people, and the people who have taken the government action to get the fast investigations in the connection, the president has given their special report."
Featured Image Credit: PA