UPDATE 2-U.N. calls for end to Chad fighting

(Adds Security Council meeting starting, diplomatic comment)

By Patrick Worsnip

UNITED NATIONS, Feb 3 (Reuters) - U.N. Secretary-General Ban Ki-moon called on Sunday for an end to fighting in Chad, where rebels have besieged the presidential palace, and the Security Council met to address the situation.

"He is profoundly alarmed by the dangerous situation in Chad, particularly in light of heavy fighting in several parts of the capital city of N'Djamena," a spokesman for Ban said.

"He is particularly concerned at the deterioration of the serious humanitarian situation of some 285,000 refugees and 180,000 internally displaced persons."

Several hundred people have been injured in two days of street fighting after a rebel assault, the second to hit the Chadian capital in almost two years. Some foreign governments were evacuating their nationals from the central African country.

Troops loyal to Chad's President Idriss Deby struck back at rebels besieging his palace in N'Djamena on Sunday and the government said it repulsed an attack by Sudanese forces in the east that it called "a declaration of war."

The Security Council met in an extraordinary Sunday session called by France together with the three African members of the council -- South Africa, Burkina Faso and Libya.

"We urge all parties to ensure the safety and security of all civilians as well as international humanitarian workers and United Nations staff in Chad," the U.N. spokesman said. "The secretary-general further called on all parties to immediately cease hostilities and engage in dialogue so as to prevent further bloodshed."