The trouble started when the security guards, in accordance with a new company circular, asked the labourers to board company buses instead of riding bi-cycles to the site, which the labourers resisted.
A senior government official said that five labourers and a press photographer suffered splinter injuries when the security guards, posted at the gate, fired.
Three of the guards were wounded when labourers threw stones during the clash, Sub-divisional Officer Subodh Kumar told reporters.
All of them have been admitted to Tata Main Hospital, he said.
The photo photographer was identified as Madan Sahu. He suffered injuries in the stomach.
Vice-President (Corporate Communication) of Tata Steel Sanjiv Paul, described the incident as "unfortunate" and said a probe had been ordered into the incident.