(CNN) -- The whereabouts of an American freelance journalist who has been working in Syria since May are unknown, a news agency reported.
It is among the key developments Friday in Syria's ongoing conflict:
Report: Whereabouts of American journalist unknown
American freelance journalist Austin Tice, who has been working in Syria, has not been heard from since mid-August, the McClatchy news agency reported Friday.
Syria has restricted access by international journalists, routinely refusing to issue visas to enter the country. Many who report from inside Syria do so by slipping across the border, as was the case with Tice, according to McClatchy's report.
Tice, 31, has been reporting from Syria since May, filing reports for McClatchy, The Washington Post and other news agencies. He documented his experiences in posts on Twitter and through personal pictures he posted at flickr.com, which garnered thousands of followers.
His last public post was on August 11 on Twitter, where he said he spent the day with members of the rebel Free Syrian Army at a pool party with music.
The U.S. State Department is working through the Czech Embassy in Damascus to learn details of Tice's whereabouts, spokeswoman Victoria Nuland told McClatchy.
The news agency is asking anyone with information on the whereabouts of Tice to contact Mark Seibel, the McClatchy Washington bureau's chief of correspondents, at firstname.lastname@example.org.
On the ground: Fighting rages in Syrian capital
Heavy fighting was reported in and around the capital, Damascus, where Syrian forces have been battling rebels for control, according to the opposition Local Coordination Committees of Syria. It also reported the heaviest shelling to date in Latakia.
At least 206 people, including 25 children, were killed in fighting across Syria on Friday, the LCC said. Of those, at least 55 deaths were reported in Damascus and its suburbs; 45 in Deir Ezzor; and 30 in Daraa.
The state-run Syrian Arab News Agency said soldiers destroyed 40 cars armed with machine guns by "terrorists" in Aleppo province. Security forces clashed with terrorists in various neighborhoods in Aleppo, inflicting "heavy losses in personnel and equipment," SANA said.
CNN is unable to independently verify reports of violence as Syria has severely limited access to international journalists.
Violence spills into neighboring Lebanon
At least three people were killed and 18 wounded Friday in clashes in the city of Tripoli, in northern Lebanon, according to the official Lebanese National News Agency, NNA.
Heavy sniper fire was heard between rival districts, the news agency said.
Two journalists, one Canadian and the other working for Sky News Arabia, were injured in the Tripoli clashes, it reported.
SANA said armed forces foiled terrorist infiltration efforts from Lebanon into Homs province.
The region: Refugee numbers swell
The number of refugees who have fled Syria for neighboring countries has climbed above 200,000, a spokeswoman for the U.N. refugee agency said Friday.
The tally includes about 74,000 Syrian refugees in Turkey, 61,000 in Jordan, 51,000 in Lebanon and 15,800 in Iraq, said Ariane Rummery, a spokeswoman for the U.N. High Commissioner for Refugees in Lebanon.
Turkey gives a slightly higher number of Syrian refugees on its territory, nearly 78,500. There are also 1.2 million people displaced within Syria, the UNHCR said.
Diplomatic front: Brahimi says Syrian people "our first masters'
Lakhdar Brahimi is the new U.N. and Arab League point man on Syria, but he said Friday that the Syrian people will be "our first masters."
"We will consider their interests above and before anyone else," said Brahimi, an Algerian and longtime U.N. diplomat.
U.N. Secretary-General Ban Ki-moon welcomed the new joint special envoy at the United Nations. Brahimi, who is replacing Kofi Annan, told Ban that despite anxiety about his new position, he is grateful and will do his best.
"Secretary-General, when you called me, I told you that I was honored, flattered, humbled and scared and still in that frame of mind. I will definitely give this my very, very best," he said.
Annan helped forge a six-point peace plan, which included a cease-fire, but the effort failed to stem the violence in Syria. The government of Syrian President Bashar al-Assad wants to know what potential solutions Brahimi will put forward.
The conflict broke out in March 2011 after demonstrators, inspired by the success of popular uprisings in Egypt and Tunisia, took to the streets demanding political reform. The movement devolved into an armed conflict after a brutal crackdown by al-Assad's forces. Opposition forces say more than 20,000 people have died.
CNN's Saad Abedine, Joseph Netto, Joe Sterling, Nada Husseini, and journalist Gul Tuysuz contributed to this report.