The European Union says it will host a high-level meeting on what it calls the "appalling tragedy" in the Central African Republic to be attended by the United Nations and donor countries on January 20.
EU aid chief Kristalina Georgieva said Monday that concerted international action is needed.
Reuters quoted U.N. officials in Bangui as saying heavy weapons fire rang out early Monday, but then subsided.
ICRC spokesperson Jean-Yves Clemenzo said the situation in the Central African Republic's capital had calmed.
"Now it's better, but there are still a lot of problems, as you can imagine, in the city," said Clemenzo.
Clemenzo said Bangui's single hospital is not enough for the city's one million residents, and that the ICRC is mainly concerned with those displaced by the fighting.
"It's a concern for the 10,000 people living in different sites in the city of Bangui. We are trying to help them. We have built two sites, several latrines. We are bringing some clean drinking water. But it's not enough," said Clemenzo.
Clemenzo said the measures are intended to prevent the outbreak of disease epidemics.
Fighting between Muslim Seleka rebels and Christian militias has killed more than 1,000 people and displaced an estimated 400,000 in Bangui this month.
Also Monday, the United Nations' children's agency said at least two children have been beheaded in this month's violence.
A UNICEF official, Souleymane Diabate, said more and more children are being recruited into armed groups, and they also are being directly targeted "in atrocious