MUMBAI: A senior journalist with an English tabloid, Mid Day, who extensively covered underworld and crime for over two decades, was shot dead in broad daylight today by four unidentified bike-borne persons who pumped five bullets on him from behind in suburban Powai. Jyoti Dey (56), who was working as editor (special investigation), was shot dead by unidentified persons in Powai at 1530 hours, joint police commissioner (Law & Order) Rajnish Seth said.According to additional police commissioner, Vishwas Nagre Patil , four persons on two bikes fired a number of rounds at Dey, who was also riding a bike, from behind this afternoon in Hiranandani area of Powai.Following this, he was rushed to nearby Hiranandani hospital where he was declared dead, Patil said.The shooters escaped from the spot after firing five rounds, police said, adding further probe was on.Expressing shock over the killing, Maharashtra PWD minister Chhagan Bhujbal said the journalist did not 'target' any gang or mafia in particular.Asked if the killing could be linked to elements from the underworld or the oil mafia, Bhujbal, a former home minister, said, "Dey was a very honest person. He used to write on underworld. He was not targeting anyone in particular, whether any gang or any (oil) mafia".Mid Day editor Sachin Kalbag said the killing of Dey was a tremendous loss to the newspaper. Kalbag sad Dey ws called a "guru" by budding crime reporters for his expertise in investigative reporting.Kalbag said it was too early to ascertain the motive behind the killing.State home minister RR Patil said Dey had not made any complaint regarding any threat to his life. Patil said the government has taken the killing of senior journalist J Dey "very seriously" and senior police officials have been asked to immediately nab the culprits. "I have spoken to the Mumbai police commissioner, and Joint Commissioner (Crime) who are visiting the scene of crime. I have given instructions that the culprits be arrested as soon as possible," Patil saidPolice sources however said Dey, who recently ran a series of news reports on oil mafia, had received threats from anti-social elements.Patil said the identity of the killers could not be ascertained for the moment but whoever is behind the crime will be arrested.Chhagan Bhujbal said Dey's killing appeared to be pre-planned."The way he (Dey) was killed with bullets, it is well planned. Some mafia will be behind it," he said. "We are very much shocked to hear this tragic news," Bhujbal said.He recalled having attended a book release of 'Zero Dial', written by Dey about police informers, three months ago, in presence of actor Ajay Devgan."He always used to write about underworld. He had given a number of stories but he was not targeting anybody. He was simply giving the in and out, how these gangs were working that's all," he added. "I think police will come to know in some time why he was killed," Bhujbal said.Sachin Kalbaug said the Mid Day newsroom was in a state of shock."Dey was one of the senior most journalists, a well known crime reporter of Mumbai. His loss is a tremendous loss to newspaper," he said."We are in a state of complete shock. It is too early to say why this has happened and how it happened. No indications that he was working on a big story now which would have made anyone uncomfortable."Yes, he has broken big stories all his life. He is in journalism for more than two decades now. Only police would tell you which underworld person, if at all, you know is responsible for his over two decades of investigation reporting....It is not for me to speculate, I can tell you that he was not doing any big story now," Kalbaug said.Dey has worked with major newspapers including Indian Express and Hindustan Times.Last month, tabloid employee and veteran journalist Tarakant Dwivedi alias Akela was arrested by the Government Railway Police (GRP) under relevant sections of Indian Penal Code and Official Secret Act after he had allegedly entered the government armoury in CST railway station and filed a news report about poor handling of armoury June last year.Subsequently, the tabloid's employees headed by Dey and various journalist associations met home minister RR Patil, lodging protest against the police action on Akela and termed the action as a grievous assault on the freedom of the press.