WASHINGTON (Reuters) - The United States urged the Serbian government to help protect the U.S. Embassy in Belgrade, a State Department spokesman said on Thursday after protesters in Serbia’s capital attacked the embassy to protest Kosovo’s independence.

“We are in contact with the Serbian government to ensure that they devote the appropriate assets to fulfill their international obligations to help protect diplomatic facilities, in this case our embassy,” State Department spokesman Sean McCormack told reporters.

“They (Serbia) have been up until this point very good in providing police assets to ensure that the embassy facility was protected. We want to strongly urge them and we are in contact with them to make sure that they devote the assets to deal with this situation,” McCormack told reporters.

In Belgrade, smoke billowed from the American Embassy after scores of protesters broke into the building cheered on by crowds outside. Some 200 riot police arrived about half an hour later, beating and arresting some of the rioters and driving the rest away.

McCormack said the State Department had an open line to the embassy, but said he had few details of what was happening.

“Last reports I had were that they were in the consular building,” he said of the protesters.

He said he believed the attack came after business hours, when the ambassador and staff were not there. His understanding was that the only people in the embassy at the time of the attack were security people and Marine guards.

Responding to a question, McCormack said he had no indication that Serbian police had been reluctant to protect the embassy.

“You know, I have no indication that that is, in fact, the case. ... Once this incident has been resolved, I’m sure we’ll have a chance to go back and look at the forensics and see exactly what happened. But what’s important now is that the government act, get the forces there necessary to deal with the situation,” he said.