Sinn Fein said today it was "unhappy" at the behaviour of Orange Order bands who marched through Belfast on Saturday playing songs likely to offend Catholics.
"Not just a handful but most of the bands taking part" had defied Parade Commission instructions to keep to hymns while marching past a Catholic church.
That ruling was intended to reduce the risk of the march ending in violence, as a number of Orange Order anthems can be seen as inciting hatred against nationalists.
Around 30,000 members of the so-called "loyal orders" marched through the city to mark the centenary of the Ulster Covenant, a declaration signed by nearly half a million Irish protestants in 1912 in opposition to Irish independence.
The march was heavily policed but no violence was reported.
St Patrick's church administrator Father Michael Sheehan said: "I think a degree of respect was shown that hasn't been shown before."
nBelfast SDLP councillor Nichola Mallon lodged a formal complaint against British National Party leader Nick Griffin with the Northern Ireland Police Service today.
Ms Mallon said a tweet posted by Mr Griffin was an incitement to hatred.
The bigoted BNP boss had tweeted: "So Ulster pics have upset my Republican stalkers. Tell you what, the bodran [sic] can't match the lambeg (drum), you Fenian bastards."