Indonesia has arrested 16 people suspected of plotting to kill police with cyanide and pen guns, a gun fashioned to look like a pen, authorities said.
Local media reported that some of the suspects had links to the al-Qaeda linked Jemaah Islamiyah group.
The suspects were arrested over the past three days in the capital, Jakarta, and other locations based on confessions from people captured in Central Sulawesi after two police officers were slain last month, Colonel Boy Rafli Amar, a national police spokesman, said.
"There is suspicion that they have plotted to attack policemen, but in a different ways, including by using cyanide,'' Amar told reporters.
"The group planned to spread cyanide in police dormitories and canteens. Bottled water was also to be used as a delivery method. This is a new model of terror attack."
Extremists in Indonesia have increasingly targeted police in the past year or so as an ongoing security crackdown has disrupted their ability to launch large-scale attacks.
'Intimidate the government'
Al Jazeera asked James van Zorge, a partner at Heffernan and Associates, a leading risk consultancy in Jakarta, who he thought was behind the plot.
Van Zorge said: "We've been talking to some security analysts, they believe these are smaller groups only with loose affiliations with Jemaah Islamiyya and Jamaah Ansharut Tauhid.
"These groups are primarily small cells looking to engage in low cost, small-scale attacks mostly against security forces.
"I think this [latest alleged plot] is probably part of a larger strategy to intimidate the government as we approach Friday."
The verdict in the trial of Abu Bakar Bashir, the spiritual head of Jemaah Islamiyya, is set to take place this upcoming Friday. The cleric is accussed of funding a training camp for fighters in Aceh.
Police have been at the forefront of Indonesia's security crackdown since the al-Qaeda-linked nightclub bombings on the resort island of Bali in 2002.
In September last year, a man tried to blow up a police post near Jakarta with a homemade bomb strapped to his bicycle.
The man, who carried a note saying he wanted to avenge the arrests and killings of Muslim fighters, was injured when the explosive detonated prematurely.
In April, a suicide bomber blew himself up in a mosque in West Java where police were preparing for Friday prayers, wounding 30 people, mostly policemen.