Jakarta (AFP) -
An Indonesian cathedral was rocked by a suicide bombing Sunday that wounded 20 as worshippers celebrated the start of Holy Week, an attack slammed by the country's president as an 'act of terror'.
Two suspects behind the powerful blast were killed as they rode a motorbike into the compound of the church in Makassar city on Sulawesi island, authorities said.
'A suicide bombing occurred at the cathedral in Makassar,' Indonesia's chief security minister Mahfud MD told reporters in the capital Jakarta.
'The two (bombers) died.'
Authorities had not previously confirmed that the bombing, which happened around 10:30 am local time (0330 GMT), was a suicide attack.
Twenty church officials, congregants and security staff were injured by debris from the blast, authorities said.
A church security guard tried to prevent the two perpetrators -- who have not been identified -- from entering when the explosion occurred, they added.
One witness described hearing two 'very strong' blasts and then seeing plumes of smoke.
'There were several injured people on the street. I helped one woman... who was wounded and covered in blood,' Yosi, who like many Indonesians goes by one name, told AFP.
'Her grandchild was also injured. There were body parts everywhere.'
It was not clear if the victims' wounds were life-threatening.
'We were finishing the service and people were going home when it happened,' Pastor Wilhelmus Tulak told reporters.
Forensic investigators have been poring over body parts scattered at the scene in a bid to determine the attackers' identities.
No one has claimed responsibility for the attack.
Churches have been targeted in the past by extremists in Indonesia, the world's biggest Muslim-majority nation and home to several religious minorities including Christians, Buddhists and Hindus.
- 'Act of terror' -
Indonesian President Joko Widodo said he 'strongly condemned this act of terror'.
'Terrorism is a crime against humanity,' he said.
'I call on everyone to fight against terror and radicalism, which go against religious values.'
Amnesty International said the bombing showed 'complete contempt' for human rights.
The explosion at the main Catholic cathedral in Makassar -- a port city of about 1.5 million -- happened just after congregants finished celebrating Palm Sunday, the first day of Holy Week, which commemorates Jesus's entry into Jerusalem.
It comes a week before Easter.
In his mass for Palm Sunday, Pope Francis said he prayed for all the victims of violence, 'especially those of this morning's attack in Indonesia, in front of the Cathedral of Makassar'.
Sunday's attack follows the arrest in recent months of dozens of militants suspected of planning terror attacks, according to Indonesia's counter-terror squad.
Indonesia has seen a string of attacks by Islamic extremists over the past two decades, including the 2002 Bali bombings which killed more than 200 people, mostly foreign tourists.
The bombings were Indonesia's deadliest terror attack.
In 2018, a dozen people were killed when a family of suicide bombers driving motorbikes blew themselves up at churches during Sunday services in Indonesia's second-biggest city Surabaya.
The family -- including two daughters aged nine and 12 -- and another family of five, which carried out a suicide bombing on a police headquarters, all belonged to the same Koran study group.
They were also linked to local extremist network Jamaah Ansharut Daulah (JAD), which has pledged allegiance to Islamic State.
JAD, which has not claimed responsibility for Sunday's attack, gained notoriety in 2016 for a gun and suicide bomb attack in the capital Jakarta that killed four civilians and four attackers -- including one who blew himself up at a Starbucks outlet.
It was the first attack claimed by Islamic State in Southeast Asia.