I'll try on some initiative ideas-
1) encourage indoor games like chess, caroms etc...
2) inform the authorities about the difficulties caused by this problem to the school authorities, like lack physical fitness and entertainment!
3) seek help from any public institutions to bring the matter to an international level!
4) inform the children about the danger of going out of the school to play!(like kidnaps, accidents etc)
5)try to involve children in physical activities like gardening and planting trees instead of playing games!
6)control the children!
7) take initiative and build a playground, from the part of all students"
contact if requires and vote as the best!