The police said the blast took place at Rasong village under Khliehriat sub-division at around two AM, leaving a crater about one foot deep at the site.
Mintu Das, 26, hailing from Assam, was killed on the spot while the injured were shifted to the nearest hospital in a critical condition.
The police did not rule out involvement of militants or mine owners in the blast and said a formal inquiry would reveal the truth.
