Police headquarter sources said the senior STF officials have rushed to Gorakhpur for starting the investigation.
The officials have instructed all the district magistrates to maintain law and order and take stringent action against rumour mongers.
At least five people were severely wounded in the three contemporaneous blasts within five minutes duration at a petrol pump, Baldev Plaza Market and Hotel York in the district.
Meanwhile, the internationl border that UP shares with Nepal and all other sensitive places in the state have been put on high alert.
Security has been strengthened at all important religious and historical monuments, including Ram Janmahoomi, Ayodhya, Sri Krishna Janmabhoomi, Mathura and Taj Mahal in Agra.
With terror threat looming large on 'Prayag' Allahabad, security has also been beefed up there. Besides, security has been tightened at all railways stations and bus terminals in the state.