The United Nations peacekeeping chief says the official government death toll of 272, including 33 civilians, in the recent fighting in the capital is likely "only the tip of the iceberg."

Herve Ladsous told the Security Council Wednesday that while a cease-fire in Juba, the capital, appears to be holding since it was declared Monday night, further clashes cannot be ruled out.

He said government forces are obstructing the movement of U.N. peacekeepers, making it hard to ascertain what has gone on since the fighting erupted last week. Ladsous said that there are reports of many civilians being barred from reaching safe havens making a higher death toll likely.