Amritsar, June 3 : Just days ahead of the 39th anniversary of the Indian Army's "Operation Bluestar", a hoax bomb call near the Golden Temple on Saturday has put the Punjab Police on alert with the deployment of a bomb disposal squad at the spot. Four persons, including three children, were taken into preventing custody for making the call to the police. Officials said the police received a call at around 1 a.m. about planting four bombs near the Golden Temple. Operation Bluestar was a military action ordered by late Prime Minister Indira Gandhi to flush out militants led by Jarnail Singh Bhindrawale holed up in the Golden Temple complex. The operation was carried out between June 1 and 8, 1984, and claimed several lives and left the shrine and complex damaged. This time keeping in view the "Operation Bluestar" anniversary that falls on June 6, Punjab Police have beefed up the security across the state to ensure peaceful observance of this week. Police teams have been conducting flag marches in the sensitive and vulnerable areas as a measure to instil the confidence among the public in all 28 police districts, officials said. Special DGP (Law and Order) Arpit Shukla said Commissioners of Police and Senior Superintendents of Police have been directed to conduct flag marches in the sensitive areas of their respective districts. Police teams have also apprehended 368 suspicious persons during flag marches. "Punjab Police will ensure peaceful observance of the Operation Bluestar anniversary for which foolproof arrangements are in place and adequate security has also been deployed across the state," said Shukla. /IANS