The dreaded H1N1 virus is back with 129 cases and 12 deaths reported in the last 20 days from four states - with the maximum of 69 cases and six deaths in Maharashtra, followed by 28 cases and five deaths from Rajasthan.

The government, however, said there was no cause for panic and these states have been asked to strengthen their surveillance to check the further spread of the virus.

"The Health Ministry is monitoring the situation and there is no cause for worry. The states where cases had been reported have been advised to step up surveillance to control the further spread of the virus," Health Secretary PK Pradhan said.

As per data released by the Health Ministry today, in the first 21 days of March, a total of 129 positive Influenza-H1N1 cases have been reported, with a total of 12 deaths. Of these, 69 cases are from Maharashtra, 27 from Andhra Pradesh, 28 from Rajasthan and five from Karnataka.

Out of 12 deaths, six have so far been reported from Maharashtra, five from Rajasthan and one from Andhra Pradesh. No death has so far been reported from Karnataka.

The Emergency Medical Relief Division of Union Ministry of Health and Family Welfare is following the developments in the states of Rajasthan, Maharashtra, Andhra Pradesh and Karnataka for H1N1 cases.

Health Ministry officials, however, ruled out any cause for alarm saying strict public health vigil is being maintained.

The virus which had spread across the world in 2009 claimed around 20,000 lives. Since then, the H1N1 cases have been on the decline across the world, including in India.

Swine flu tests are available at all government facilities and the medicine Tamiflu is available indigenously on prescription