Table-top exercises are being conducted by Army and Security Agencies.
The Army and other security agencies on Tuesday reviewed the security along the strategic 270-km Jammu-Srinagar national highway ahead of the G20 meeting.
The third G20 Tourism Working Group meeting is scheduled to take place in Srinagar from May 22 to 24.
"Table-top exercise conducted by #IndianArmy & Security Agencies in #Ramban to fine tune response to a security scenario in a coordinated manner," Jammu-based White Knight Corps of the Army posted on Twitter.
"Entire Union Territory is on highest level of alert. Specially security grid around Srinagar and Gulmarg has been enhanced as visiting delegates would be travelling in these locations," a senior official handling G20 security told NDTV.
To ensure no sleeping module is activated by Pakistan, the National Investigation Agency (NIA) has been conducting searches in valley, especially south Kashmir.
"Effort is to clamp down harder on terrorist outfits and their offshoots/affiliates operating in the Kashmir valley to disrupt peace and communal harmony in Jammu and Kashmir by spreading terror, violence and subversion," said an NIA official.
According to the source, 70 searches have been conducted in first half of the month.
Legal action is being followed after searches against Over Ground Workers (OGW) who were also acting as couriers, he added.
"Action is being taken after it's established that they were felicitating terror groups and were acting as suppliers for magnetic and sticky bombs," he said.
According to security agencies operating in Jammu and Kashmir, there is plethora of evidence to suggest Pakistan during last few weeks has been pushing terror from across the border.
"Pakistan also has activated about 30 foreign terrorists who have been hiding in valley for over a year," said a source.
According to the source, intercepted chatter also indicates Pakistan has been using encrypted messages to instigate youngsters in valley.
Earlier this month, the Centre banned more than dozen mobile messenger apps which were used by Pakistan handlers to send messages to OGWs.
The G20 summit in Srinagar would provide a great opportunity for promotion of tourism.
Delegates from 20 countries, including the United States, Canada, China, Japan are likely to attend the summit.