UNITED NATIONS (Reuters) - U.N. Secretary-General Antonio Guterres said on Friday he had serious concerns over escalating tensions between Saudi Arabia and Lebanon, and that it was essential to avert new conflict in the region.  We are indeed very worried, and we hope we won t see an escalation,  the United Nations chief told reporters.  It is essential that no new conflict erupts in the region, it could have devastating consequences.  Guterres said he had  very intense  contacts yesterday with Saudi Arabia, Lebanon and other countries in the region.  His comments come amid a deepening crisis between the two Middle Eastern nations that has thrust tiny Lebanon between Saudi Arabia and the region s other powerhouse, Iran. Earlier this week, Saudi Arabia accused Lebanon of declaring war against it, citing aggression by the Iran-backed Lebanese Shi ite group Hezbollah. On Friday, Hezbollah leader Sayyed Hassan Nasrallah accused Saudi Arabia of declaring war on Lebanon and Hezbollah. In the midst of the conflict is Saad al-Hariri, Lebanon s former prime minister, who unexpectedly resigned his post over the weekend. Lebanese authorities have said he is being held against his will in Saudi Arabia, a charge that Riyadh has denied.  
United Nations chief 'very worried' by Saudi-Lebanon tensions