A high-level meeting on Wednesday, presided over by Home Minister Shivraj Patil, reviewed the security scenario in Srinagar and adjoining areas.
The meeting followed militants' attack earlier in the day on the Tourist Reception Centre in the Jammu and Kashmir capital, where the 29 passengers scheduled to travel by the inaugural Srinagar-Muzaffarabad bus service are housed.
The bus is to be flagged off by Prime Minister Manmohan Singh on Thursday. Congress president Sonia Gandhi and Patil will also take part in the flagging off ceremony.
The home ministry is studying the situation, senior officials said after the 30-minute meeting. Patil is in touch with authorities in Jammu and Kashmir, they said.
Home Secretary V K Duggal, Intelligence Bureau Director E S L Narasimhan and Special Secretary (Internal Security) Anil Chowdhury were among those who attended the meeting.