How can i control absenteeism - people who come late to the office or take half day leave?

I work for a bpo and there are lot of people who come late to the office or take half day leave from the office and inform us half an hour before.
What strict action i can take against the same.

Discipline is core to any business productivity. Maintain a record of employees who reach late for more than 3 times a month and deduct one day leave. In case there is no leave balance then deduct loss of pay. Follow the same for early leaving as well. This policy should be approved by your BPO Management and a circular is to be issued to employees prior to implementation. Only in medical / death cases employees may leave at short notice.