Updated

Secretary-General Antonio Guterres is warning that unauthorized weapons in the hands of Hezbollah, and threatening rhetoric from the Lebanese militant group and Israeli officials, "heightens the risk of miscalculation and escalation into conflict."

The U.N. chief called on Hezbollah and Israel, who fought a war in 2006, "to exercise restraint at all times."

Guterres said in a report to the U.N. Security Council circulated Friday that allegations of arms transfers to Hezbollah continue "on a regular basis," which the U.N. takes seriously but "is not in a position to substantiate them independently.

He noted, however, that Hezbollah has acknowledged "use and display of that weaponry."

The U.N. resolution that ended the 2006 war calls for Hezbollah and all other militias operating in Lebanon to be disarmed and demobilized.