Police on Wednesday discovered a stockpile of homemade bombs in central Indonesia after uncovering plots to attack tourist destinations in the country.

“A total of 20 pipe-bombs and a 16-kilogram (35 pound) bomb housed in three Tupperware containers stuck together were found,” national police spokesman Boy Rafli Amar told AFP.

Anti-terror police found the stash of explosive materials, including detonators, nails and books on holy war, during raids in the southern district of Enrekang on the island of Sulawesi, where authorities reported increased militant activities in recent months.

Another 75 kilograms of explosive materials was found during raids in five different locations around the popular tourist town of Tana Toraja.

Last week, police shot dead seven terror suspects and arrested four on the islands of Sulawesi and Sumbawa, where the men were allegedly planning to attack holiday spots. The suspects were involved with a militant training camp in central Sulawesi’s Poso district.

Indonesia was wracked by a series of terrorist attacks during the last decade – mostly blamed on the Al Qaeda-linked group Jemaah Islamiyah – targeting westerners in the country.