On 21 September, hundreds of young men attacked the compound of a small sect, the Ahmadiyah, vandalising four buildings used for worship, torching more than 30 houses and damaging several cars in the hillside town of Cianjur, West Java, 100km southwest of the capital, Jakarta.
The attack was the latest outbreak of violence in a year that has seen more than 30 churches forcibly closed down or blockaded by Muslim mobs armed with bamboo spears, often while police stand by.
The attacks have brought the issue of religious tolerance to the fore.
Within the Indonesian Muslim community, which accounts for about 88% of the 242-million population, are several movements and organisations often at loggerheads with one another.
Moderate groups say religious freedom should be protected in one of the world's most tolerant Muslim countries.
Some would like Indonesia to become an Islamic state.
In late July, the Indonesian Council of Islamic Clerics (MUI) issued a series of fatawa (religious decrees) giving groups lobbying for Islamic law a boost.
The most publicised fatwa declared that the Ahmadiyah sect was heretical, and MUI members called on the government to ban it.
Other fatwa condemned religious pluralism, joint prayer sessions, and mixed religious marriages.
The recent decrees have boosted
those lobbying for Islamic law
But the most far-reaching fatwa with political impact was the one opposing "liberalism" and intentionally pointing fingers at groups such as the Liberal Islamic Network (JIL), which promotes modern interpretations of the Quran.
Within weeks, the Islamic Defenders' Front (Front Pembela Islam, FPI), a group thought to be behind attacks on bars and nightclubs, began trying to lobby local Muslims to expel the JIL from its home in east Jakarta.
"MUI issues the fatwas and we just carry them out," said Hilmy Bakar, a senior FPI leader, explaining that attacks on liberal groups are valid if they have been branded heretical.
But JIL's head, Ulil Absha Abdalla, decried the decrees as "stupid". Other religious leaders, as well as politicians, pointed out that banning joint prayer sessions and mixed marriages in such a religiously mixed nation was "ridiculous".
Komaruddin Hidayat, a Muslim scholar at Jakarta's Syarif Hidayatullah State Islamic University, dismissed the MUI fatwa as just a publicity ploy which was unlikely to be heeded by most Indonesians.
"It's just a business among hardliners - promoting the escalation of tension among religions," he said.
"It's just a business among hardliners - promoting the the escalation of tension among religions"
However, Muslim analysts argue that by trying to ban religious pluralism and insisting that Islam is Indonesia's official religion, the MUI is in effect attempting to move the country a step closer to introducing the Sharia (Islamic law).
Clerics from Indonesia's largest Muslim organisation, Nahdlatul Ulema (NU), stress that Muslims cannot follow such a fatwa without violating the Indonesian constitution, which protects religious pluralism.
Given that such a fatwa is only an opinion and not legally binding on Muslims, the constitution is more powerful, argue NU scholars.
And such decrees cannot be implemented unless parliament agrees to amend the constitution, they say.
Indonesia's two largest Muslim groups, NU and Muhammidiyah, together claiming 65 million followers, have always opposed the implementation of Islamic law, and most analysts doubt the push for the Sharia will get much support.
They also point out that the major political parties have in the past opposed the introduction of Islamic law when it was proposed by smaller parties.
But moderate Muslim groups see the recent intimidation of Christian churches and Ahmadiyah as part of the same trend to promote a much more conservative interpretation of Islam.
Local reports suggest that students from a Muslim boarding school were inspired by the MUI decrees to attack the Ahmadiyah compound in Cianjur last month.
Susilo Bambang's government
is accused of complacency
The 19 September attack was the second major attack on the sect in as many months. In July, several Ahmadiyah centres and compounds in towns around west Java were vandalised and a handful of local councils have banned the sect.
Numbering just over 300,000, Ahmadiyah believes that its Indian founder, Mirza Ghulam Ahmad, not Muhammad, was the last prophet.
It is this belief that prompted the Islamic Clerics Council to label Ahmadiyah as heretical.
Nahdlatul Ulema also thinks that Ahmadiyah is a deviant sect, but it is publicly defending the group's right to practise its religion freely.
"We have asked police to take steps so there is no more destruction. NU doesn't support the destruction of places of worship," says senior NU leader Achmad Bagda.
"If people don't agree with Ahmadiyah, they don't have to follow it," he added.
The Liberal Islamic Network has offered legal assistance to Ahmadiyah and will also organise an investigation into the attacks.
The pressure from Muslim moderates appears to have worked. Unlike the last attacks on Ahmadiyah property, the police appear serious about prosecuting the attackers this time, arresting 12 suspects.
NU has also been lobbying the police and local governments to stop Muslims from intimidating Christian groups.
Over the past year, more than 30 churches have been closed down under pressure from Muslim groups.
"We said to police don't allow this [church closures] to be used to instigate chaos among the community," said Sofyan Yahya, the head of NU's West Java chapter.
The FPI believes Indonesia should
become an Islamic state
Conservative groups deny they are trying to spark an inter-religious conflict, claiming they are just upholding Indonesian law.
"Those closed were not churches, but private houses, used by Christians as prayer places without a government permit," said Habib Rizieq Shihab, the head of the Islamic Defenders' Front, which, along with the Anti-Apostasy Movement, has been accused of organising the closures.
Christian ministers admit they have been forced to use shops and homes as churches, because under Indonesian law religious groups have to get permission from both the Religious Affairs Ministry and the neighbouring community before they can build a place of worship.
Some Protestant communities say they have been lobbying their local community for more than a decade and still have not received permission to build a church.
The bylaw, which in effect allows a single Muslim to oppose the construction of a church, is biased against minorities, church leaders say.
"That is the weakness of our government now. They are not able yet to give freedom to people as it was instructed by the constitution," says Richard Daulay, the secretary-general of the Indonesian Communion of Churches.
Pressing the government
The Indonesian government says it will revise the bylaw so that a joint religious council, and not local residents, will have the authority to approve the construction of churches and other religious buildings.
But the Liberal Islamic Network, along with NU and Muhammidiyah, says it is not enough to change the law. They argue violent groups should be prosecuted for trying to take the law into their own hands, otherwise they will continue to intimidate minorities in the name of Islam.
"They say they do this in the name of religion, but all religions reject it," said Mahmadah.
Others see the attacks on churches as an attack against Indonesia's religious tolerance.
"This threatens our principle of unity in diversity," said Achmad Bagda, a senior NU leader, quoting a line from the Indonesian constitution.