(A section of the peace wall that divides Catholic and Protestant communities in Belfast wraps around houses in Cluan Place, east Belfast October 27, 2012. The first barriers were built in 1969, following the outbreak of the Northern Ireland riots known as “The Troubles.” They were built as temporary structures meant to last only six months, but they have multiplied over the years, from 18 in the early 1990s to 40 today; in total they stretch over 13 miles (21 km), with most located in Belfast. REUTERS/Cathal McNaughton )

The proportion of Protestants in Northern Ireland has fallen below 50 percent for the first time, census figures showed on Tuesday, raising the prospect that the growing numbers of Catholics could upset a fragile political balance.

A wave of street violence in Belfast over the past days has been fuelled by the sense that nationalists, who are mainly Catholic and want Northern Ireland to be part of Ireland, are in the ascendance.

Nationalists share power with predominantly Protestant Unionists in the British-controlled province under a 1998 peace deal that ended three decades of sectarian violence that killed 3,600, with Unionists controlling the post of first minister thanks to their majority.

However, the proportion of Protestants fell to 48 percent from 53 percent 10 years ago, the results of the 2010 census showed, while the proportion of Catholics increased to 45 percent from 44.