Nine suspected terrorists, who were reportedly planning bomb attacks in Indonesia's capital city of Jakarta and other places, were arrested from across the country Indonesia over the weekend. 

The arrested terrorists belonged to two terror groups, including one linked to the Islamic State, according to reports. They were found with bomb-making explosives as well as an Isis-like black flag. 

The Indonesian authorities were tipped off by Australian Federal Police and the FBI, The Sydney Morning Herald said. 

Some of the targets of the terrorists were Shia communities in the country, which has the highest Muslim population. 

Among the suspected terrorists were a teacher and a student from an Islamic school, according to the Australian Associated Press. A flag, "similar to an ISIS flag", was found from the Islamic teacher's house. 

Indonesia's counter terrorism unit, Detachment 88, conducted multiple raids across the Java Island on Friday and Saturday and discovered materials for a potential terror attack. 

"Evidence found in his house were books on Jihad, electronic components, fertiliser, nails, ball bearings and a map of Jakarta and Greater Jakarta," Sukoharjo police chief Andi Rivai told SMH of a suspected terrorists arrested from central Java. 

Security has now been put on high alert at strategic locations in the country, including airports and outside embassies, The Jakart Post reported. Indonesian authorities have reportedly been warned to watch out for terror threats up to the New Year's. 

On Monday, Australia and Indonesia signed an agreement to boost intelligence-sharing to combat terrorism.