Deputy Commissioner of Police (Special Cell) Pramod Singh Kushwah said the accused, Mukadir Islam, (22), Ranjeet Ali (24) and Luit Zameel (24), all residents of Goalpara, were arrested on Sunday.
Of the deceased, five were from West Bengal, two each from Jharkhand and neighbouring Assam and one from Mizoram's Lunglei district, the official said.
Dhubri is the worst hit with over 8.72 lakh people affected, followed by Barpeta with more than 4.78 lakh people and Goalpara with around 4.28 lakh population.
Several rebel Maharashtra MLAs are currently camping in the Radisson Blu Hotel in Guwahati.
They have been booked under different sections of the Unlawful Activities (Prevention) Act, IT Act and CrPC, a senior police officer said.
The flood situation in the three districts of Barak Valley -- Cachar, Karimganj and Hailakandi -- remained critical as the water levels of Barak and Kushiara rivers continued to rise, inundating vast tracts of land, officials said.
Two more died in the state today. With this, the total number of people losing their lives in this year's flood and landslide has gone up to 115 across the state -- 89 were killed in flood-related incidents and 26 in landslides.
With two more deaths, the fatalities due to flood this year has gone up to 18.
Assam reeled under devastating floods caused by incessant rain, with Prime Minister Narendra Modi taking stock of the situation and Chief Minister Himanta Biswa Sarma visiting several relief camps sheltering affected people on Saturday, officials said.
Legal experts and opposition parties in Assam have slammed the police for arresting the teacher and the judiciary for sending her to jail as consumption of beef, even in public places, is not illegal in the state.
The total number of people killed in flooding and landslides in the state this year has gone up to 76. While 50 people were killed in inundation, 26 died due to landslides.
In a record turnout, more than 90 per cent voters exercised their franchise in 14 constituencies in Assam in the second and final phase of just concluded assembly polls.
With the fresh fatalities, the total number of people losing their lives in this year's flood and landslides across the state has gone up to 42.
In another major crackdown on the Popular Front of India, police along with other investigative agencies conducted raids across several states on Tuesday.
The situation in the state remained grim on Monday.
The Armed Forces (Special Powers) Act, 1958, was completely withdrawn in Meghalaya in 2018, Tripura in 2015 and Mizoram in the 1980s.
The flood situation in Assam remained grim after fresh heavy rainfall in Meghalaya's Garo hills and Goalpara district as the death toll mounted to 40.
Army staged a flag march on Wednesday in areas hit by violence in Assam's Goalpara district and shoot-at-sight orders issued even as Chief Minister Tarun Gogoi said he would recommend a CBI inquiry into the violence in which the toll rose to 19.
Suspected United Liberation Front of Asom militants detonated an improvised explosive device targeting a Central Reserve Police Force team in Assam's Goalpara district in the wee hours of Thursday but none was hurt.
The overall flood situation in Assam further worsened on Thursday as fresh areas came under water with the death toll rising to 30 and many others went missing in a boat capsize in Goalpara district.
With the recovery of four more bodies today, the death toll mounted to 36 in Assam floods that affected about 10 lakh people in 13 districts and rendered majority of them homeless.
Road and rail links between lower and upper Assam remained disrupted for the fourth day on Tuesday.
A person was seriously injured in an explosion while making a bomb inside his residence at Sivasagar town in eastern Assam. The police also recovered a huge cache of explosives and ammunition from a rubber plantation in Goalpara district of western Assam on Tuesday.
One person was killed and three others injured on Wednesday in a bomb blast in Assam's Goalpara district, suspected to have been carried out by ULFA's anti-talk faction.
A militant of the United Liberation Front of Assam was killed in an encounter with the security forces on Tuesday.
The bomb was noticed on Tuesday night by a member of the audience inside the hall at Ambari in West Goalpara during the interval. The hall authorities then halted the film's screening and informed the police.
The worst affected districts are Lakhimpur, Golaghat, Bongaigaon, Jorhat, Dhemaji, Barpeta, Goalpara, Dhubri, Darrang, Morigaon and Sonitpur
The flood situation in Assam worsened on Saturday with four more deaths reported and over 6.5 lakh people being affected in more than 1,400 villages due to incessant rains across the state.
"Why did the BJP government in 2018 sanction Rs 46 crore? This shows Modi is a liar", Gogoi asserted.
The death toll in Assam in the current flood rose to 30 on Wednesday with 14 bodies recovered from worst-affected Goalpara and Kamrup (rural) districts even as relief and rescue work continued round-the-clock.
Currently, the Brahmaputra at Guwahati, Nimatighat in Jorhat, Tezpur in Sonitpur, Goalpara and Dhubri towns, while the Barak at AP Ghat in Cachar and Badarpurghat in Karimganj are flowing above the danger mark.
The minister also said the Bengaluru-specific anti-terrorist squad (ATS) probably will be operational in November first week.
At least two people, including a woman, were killed when police opened fire on a mob that tried to attack a police station at Krishnai in Goalpara district in western Assam. Curfew was clamped in Goalpara after the incident. About ten people, including policemen and Central Reserve Police Force personnel, were injured in the clash. The mob, which stormed the police station, was trying to free ten people who had been arrested by the police on charges of abduction and murder.
Trouble erupted when the demonstrators, demanding exclusion of non Rabha-Hasong villages from the upcoming Rabha-Hasong Autonomous Council elections, set ablaze a long distance bus and refused to lift their blockade on the highway despite hundreds of vehicles being stranded on both sides of the road, officials said.
Six ULFA anti-talk insurgents were apprehended with arms and ammunition by a joint Army and Meghalaya police team in Meghalaya along Assam border, a defence officer said in Guwahati on Wednesday.
The war veteran, who retired from the Army in 2017, was awarded the President's Medal in 2014.
1 person died in Dibrugarh and Tinsukia district each taking the toll in current phase of floods to 31.
Each of Assam's border disputes has its own legacy of claims and counter-claims:
'Expect very heavy rainfall at some places in Uttar Pradesh and Bihar along with sub-Himalayan West Bengal comprising of Alipurduar, Cooch Behar, Darjeeling, Kalimpong, Siliguri, Jalpaiguri, including Sikkim, parts of Arunachal Pradesh, and parts of lower Assam, Rangia downward like Barpeta, Goalpara, Dhubri along with parts of Meghalaya.'
More than 39.8 lakh people in 27 of the 33 districts in the state were affected by the deluge on Thursday.