However, no incidents of intrusions or other security related lapses were reported at airports in other three regions -- Mumbai, Kolkata and Chennai -- this year so far, Minister of State for Civil Aviation K C Venugopal informed the Lok Sabha.
According to statistics placed before the House, Delhi region reported one case last year while five such cases were reported in 2010 but none in 2009.
Mumbai Region saw no security related lapses last year while two were reported in 2010 and one in 2009.
In Kolkata region, three cases were reported last year and six each in 2009 and 2010.
Chennai region had five security lapse cases last year while the figure was six for 2010 and two for 2009.
A study team from International Civil Aviation Organisation, which conducted a detailed study on aviation security arrangements and procedures in India, recommended creation of a dedicated Aviation Security Force and restructuring of Bureau of Civil Aviation Security to tide over acute shortage of manpower, Venugopal said.
To another question, he said, sky marshals have been travelling on-board aircraft on specified routes for strengthening security in planes.
On the incident involving CISF and Custom personnel at Mumbai airport on October 3 when two gates remained unattended, Venugopal said a preliminary inquiry found that the barriers at Gate No 1 and 6 were closed during the whole incident and as such security was not compromised.