Horizontal line on screen

Recently I notice one or more horizontal line across the screen of my tablet (iPad).

I have tried reset it by holding down Power button and Home key, and also installed the latest operating system (iOS 10.2.1) but the issue still persists.

I was unable to contact Apple Support online because it kept asking me to try again.

Is this hardware issue? Is one year warranty applicable for replacement or repair?

Hopefully someone can tell me before I make a visit to nearby Apple reseller shop.

Thank you!