The United States said Thursday it will ask the UN Security Council to unequivocally condemn attacks on embassies in the Serbian capital that apparently were sparked by Kosovo's unilateral declaration of independence. US Ambassador Zalmay Khalilzad said he was "outraged" at Thursday's attack on the US Embassy in Belgrade, where masked men set fire to an office, sending flames shooting up the side of the building. The neighboring Croatian Embassy also was targeted by the same group of protesters. Smaller groups attacked police posts outside the Turkish and British embassies in another part of the city but were beaten back. "I'm going to go into the Security Council," Khalilzad said, "and ask for a unanimous statement to be issued expressing the council's outrage, condemning the attack, and also reminding the Serb government of its responsibility to protect diplomatic facilities." The council was scheduled to meet Thursday afternoon on the Ethiopia-Eritrea border dispute. The US was also expected to formally introduce a resolution that would increase sanctions on Iran for refusing to suspend uranium enrichment. The attacks on the embassies came four days after Kosovo declared independence from Serbia. The Serbian parliament has declared the action "null and void" but Kosovo's independence has been recognized by the US and a number of European countries. In Belgrade, elite police paramilitaries drove armored jeeps down the street outside the US Embassy and fired dozens of tear gas canisters to clear crowds. The protesters fled into side streets where they continued clashing with the police as half-a-dozen fire trucks moved in to swiftly put out the embassy fire.