Indonesian police say they have arrested 11 terrorists who were planning deadly attacks on the US embassy and consulate in the country.

“The group’s objectives were to attack the US embassy in Jakarta and consulate-general in the eastern Javanese city of Surabaya,” national police spokesman Suhardi Alius told reporters.

Anti-terror police made the arrests in Jakarta, and three other cities after investigations led them to a new terrorist network known as Hasmi. Explosive materials were discovered in central Java as well as in Bogor, on the outskirts of Jakarta.

Indonesia has not seen a major attack for almost three years and authorities had thought Al-Qaeda-linked Jemaah Islamiyah, the group blamed for the 2002 bombings in Bali that killed 202 people, was becoming weak.

But, according to the Bangkok Post, smaller terror cells aspiring to an Islamic caliphate through violent means have emerged. And though none have carried out any serious attacks, the latest incident is worrying authorities.