Delhi was put on heightened vigil on Wednesday night with deployment of armed police personnel across the city after five bomb blasts took place in Pune.
Roads were barricaded and vehicles checked while security was strengthened at vital installations like the Parliament and other key buildings.
Police also strengthened security at Jantar Mantar where Anna Hazare and his team are on an indefinite fast following the explosions in Pune. A bomb disposal squad conducted searches at the protest venue, a senior police official said.
Around 100 more police personnel were rushed to the venue late in the night. Police closed two of the three entry points to the venue as a precautionary measure.
Roads near Prime Minister Manmohan Singh's official residence were also barricaded.
Deployment of police personnel was also increased at India Gate.