What unique and traditional event takes place in the Philippines on Valentine’s?

While most of the world exchanges flowers, this country turns Valentine’s Day into a mass celebration with hundreds (sometimes thousands) involved at the same time. It’s romance on a breathtaking scale—and a powerful reminder of what Valentine’s can truly stand for.
In what country did riots break out on Valentine’s in 2013, 2014, and 2015?

In what country did riots break out on Valentine’s in 2013, 2014, and 2015?