A married couple - Santosh Roy and Jaimoti Roy - were nabbed from Salsalabari of Alipurduar in Jalpaiguri district, police said. The district court later sent them to police custody for ten days.
The couple - members of the fourth batch of KLO ultras - are linked to the outfit's action squad deputy commandant Tarun Thapa.
"They were preparing to flee to Assam," said the police officer.
Meanwhile, KLO militant Choton Roy was arrested for his alleged involvement in the firing on a bus in Malda district Dec 27.
"He was arrested from a hideout. Roy has confessed that he was part of the six-member squad that attacked the Bamangola-bound bus. We have extracted some other useful information from him," said Malda's Superintendent of Police Kalyan Mukherjee.
The Malda district court later sent him to seven days police custody.
Six people were killed in the Dec 26 blast at Bajrapara area of Jalpaiguri, while at least three people were injured when militants fired at the bus in Habibpur area of Malda.
Police suspect the KLO was behind both the incidents. But the outfit has denied its involvement.
The KLO has been demanding a Kamtapur state comprising six districts - Cooch Behar, Darjeeling, Jalpaiguri, North and South Dinajpur and Malda - of West Bengal and four contiguous districts of Assam - Kokrajhar, Bongaigaon, Dhubri and Goalpara.
--IANS (Posted on 03-01-2014)