Kolkata and parts of West Bengal were on Wednesday rocked by successive mild tremors in a span of less than two hours, following the massive temblors in Sumatra.
The first tremor was felt at 2.42 pm and the second at 4.13 pm, said Regional Meteorological Centre Director G C Debnath.
Tremors were also felt in North and South 24 Parganas districts adjoining Kolkata and in Darjeeling and Siliguri in north Bengal, official reports said.
West Bengal Chief Minister Mamata Banerjee, who returned from Delhi, told reporters at the airport that district administrations have been alerted and people should not panic.
A high alert was sounded along the coast with warnings issued to fishermen and tourists.
Sea water might rise along the coast, Disaster Management Secretary Indewar Pandey said.
An alert has also been issued to district magistrates in North and South 24 Parganas, East and West Midnapore and Howrah districts, Irrigation Minister Manas Bhuina said.
The minister said that the leave of all department employees has been cancelled for the next seven days.
A control room has been set up at the Irrigation Department headquarters at Salt Lake.
Metro services in the city were suspended for 48 minutes, said Deputy General Manager (General) of Metro Railway Pratyush Sinha.
Sinha said the temporary shut-down enabled railway engineers to inspect the tunnels for any damage or subsidence of the tracks and any damage to electrical installations.
According to reports, some buildings in the metropolis developed minor cracks.
The tremor led people and employees in high-rise buildings to move out on the streets. At Sector V in Salt Lake, some offices closed for the day.
