The powerful quake, with its epicentre in adjoining Sikkim, was followed by two aftershocks after 6 p.m. Sunday.
Four people died in Kalimpong, and one each in Siliguri and Kurseong of Darjeeling district.
A tea garden labourer died in Malbazar of Jalpaiguri district while two deaths were reported from North Dinajpur district, said divisional commissioner (North Bengal) A.K. Singh.
One more person fell victim to heart attack in Siliguri unable to bear the tremor and the aftershocks, a police officer said.
Many buildings developed cracks and the neighbouring Himalayan state of Sikkim was cut-off from north Bengal by landslides triggered by the tremors in Darjeeling's Kalimpong and Kurseong hill sub-divisions.
Many patients in a nursing home of Siliguri were injured, North Bengal Affairs Minister Gautam Deb said late Sunday.
The National Highway 31 A -- considered the lifeline of Sikkim -- was blocked due to landslides, cutting off the state's road link with the outside world. Efforts were on to re-open it.
Doctors in a Siliguri hospital said around 40 people had been admitted while 40 others were discharged after being given first-aid.
At least 50 others were treated in different nursing homes and hospitals of the district, the doctors said.
Power supply was disrupted in areas near Sikkim-Kalimpong, adjoining Jalpaiguri and Cooch Behar districts. A sub-station was damaged in Siliguri but the supply was restored late Sunday.
"Most of the north Bengal areas, including Darjeeling, were lashed by heavy rains that continued through Sunday night. The situation deteriorated with landslides in Kalimpong and Kurseong," Deb said.
A fire brigade official said the quake damaged power lines, disrupted telecom networks, and caused wall collapses and gas leakages.
West Bengal Chief Minister Mamata Banerjee announced compensation of Rs.2 lakh to the families of each of the dead and later toured the affected areas of Kurseong and Siliguri by taking a circuitous route from Bagdogra.
In Kurseong, she went to the Long View Tea Garden which was devastated in a landslide leading to one death.
The chief minister held an emergency meeting with district officials and discussed the steps needed to be taken to reach relief and undertake repairs.
Banerjee also added that rescue teams have reached various parts of north Bengal that was hit badly by the quake, which had its epicentre in Sikkim.
"We will also assess the situation regarding damage to houses and other damage and then chalk out a compensation for that also," Banerjee said earlier in Kolkata.