Bharti Airtel, India's second-largest telecom operator, has announced a hike in mobile tariffs by 10-21%. Among unlimited voice plans, the ₹179 28-day prepaid plan has been revised to ₹199 and the ₹455 84-day plan has been revised to ₹509. Bharti Airtel said the company welcomes the industry announcement to 'repair tariffs'. Revised mobile tariffs will be effective from July 3.