Dispur, Apr 23 : Prime Minister Manmohan Singh and his wife Gursharan Kaur on Thursday cast their votes here during the second phase of the general elections.

Authorities beefed up security at Booth number 156 located at the Dispur Government Higher Secondary School at Sarumatoria, where Dr. Singh and his wife reached to cast their votes.

Singh is officially a voter from Guwahati.

A powerful bomb blast in a crowded parking area killed four people in Guwahati in the first week of April, ahead of Singh''s visit to the state.

Police suspected that the United Liberation Front of Asom (ULFA) was behind the blast. (ANI)