Terrorism in Indonesia has been reduced to "low-tech, low-competence, low-casualty attacks" by weakened groups – but could shift up to a more deadly threat if Indonesians fighting in Syria return home with greater professionalism, a new report says.

"Weak groups need to prove themselves," said Sidney Jones, director of the Institute for Policy Analysis of Conflict, the author of the report "Weak Therefore Violent: The Mujahidin of Western Indonesia." "This may explain why we have more terrorist plots today than in the past, even if most of them fail."

The international connections and skill sets of terror network Jemaah Islamiyah have been dispersed as counter-terrorism authorities successfully dismantled the group.

Government data show 75 attacks between 2010 and 2013 – a significant rise on previous years – but they have been largely ineffective and the last three suicide bomb attacks killed only the bombers.

"It is reassuring that most of the would-be terrorists in Indonesia lack international experience and international connections, but the longer the Syrian conflict continues, the greater the chances that more Indonesians will get involved," the report read.

Terrorism in Indonesia is now characterized by low-skilled militants who may feel that violence is the only way to gain legitimacy, but do not possess the wherewithal to carry out a large attack.

Instead, attacks on the police have become more frequent, with several shootings and stabbings of officers in Jakarta's satellite cities this year. The report indicates that militants may be targeting police out of vengeance for the high number of terrorists that have been killed during police operations.

While President Susilo Bambang Yudhoyono suggested earlier this year that the military could assume a role in the hunt to root out the country's militants, Jones says the task should remain the province of the police.

"Given the fact that Indonesia does not have a repressive government, is not under occupation or attack and has no active communal conflicts at the moment," the report reads. "The only real motivation for temporarily disengaged jihadis to return to battle is to avenge... deaths at police hands.

"This means there is an urgent need for counter-terrorism police to review the procedures that are resulting in so many deaths of suspects and make a more concerted effort to ensure that future targets are captured alive."

Of pressing concern, however, is the potential for a charismatic, highly skilled leader-in-the-making to change this state of affairs.

The foreign ministry believes there are around 50 Indonesians fighting in Syria – where contacts, military experience and training can be easily won.

The report notes that the number of Indonesians who have traveled to Syria is a "reminder that the current sense of distance from the global jihad can easily change as more Indonesian fighters go to Syria and return."