Thiruvananthapuram, May 23 : Kerala's Confederation of Private Bus Operators, comprising about a dozen different organisations, on Tuesday announced that if their demands are not met, they will be going on an indefinite strike from June 7. Among their demands that have been now put before the Kerala government is that the minimum charge for students should be raised to Rs five and there should be an age limit to the student category. The other demands include that the present practice of issuing permits to private buses should continue and there should not be any distance restriction, besides limited stop, on buses. Incidentally the notice for the indefinite strike has been given at the time the educational institutions open for a new academic year, next month. Across Kerala, there are around 12,500 private buses, which are the backbone of the daily travel of the common man as the state run Kerala State Road Transport Corporation has around 6,500 buses only. /IANS