VATICAN CITY (AP) — Joyous Congolese dancing and singing have enlivened St. Peter’s Basilica, as Pope Francis celebrated a special Mass for Catholics from the violence-wracked African nation and denounced arms suppliers for helping to fuel the conflict.

The whoops of joy and the chorus of rhythmically-swaying Congolese approaching the altar Sunday was a vivid contrast with the usual solemn religious ceremonies at the Vatican basilica.

In his homily, Francis prayed that conflict cease, noting peace was “gravely threatened in the east of the country.’’ He decried weapon suppliers, lamenting “conflicts fed by those enriching themselves with arms.”

Recently, rebels in eastern Congo have targeted Ebola response workers, compounding difficulties in containing the outbreak.

A Mass’ end, a Congolese nun urged Francis, who has expressed hopes in the past to visit Congo, to come.