Ms. Pillay told an urgent meeting of the U.N. Human Rights Council that “hundreds of people have reportedly been killed since the start of this latest assault in the beginning of February 2012.”
She called on Syria to end all fighting, allow international monitors to enter the country and give unhindered access to aid agencies.
In Beirut, a British Embassy official told the Associated Press that London is working to repatriate Mr. Conroy, who was injured in the Homs along with French journalist Edith Bouvier.
The Local Coordination Committees spokeswoman said Ms. Bouvier remained behind in Homs.
American Marie Colvin and Frenchman Remi Ochlik were killed in the same attack and their bodies are still in Syria.
A spokesman for Britain’s Foreign Office said the British government could not immediately confirm the reports.
“All the necessary work is being done on repatriating Marie Colvin’s body and ensuring Paul Conroy gets to safety. For security reasons we can’t give you any more detail of that at the moment,” said the spokesman, on condition of anonymity in line with policy.
The British-based Syrian Observatory for Human Rights said shelling of the central town of Halfaya killed at least four civilians and wounded dozens, many of them seriously.
The Local Coordination Committees said 20 people were killed and 100 wounded in the town.
Both groups said the rebel-held neighborhood of Baba Amr in the central city of Homs was under intense shelling. The Local Coordination Committees said 12 people were killed in Homs, while the Observatory for Human Rights said five.
Independent voices from the TWT Communities
The cold hard truth about politics in America today and the state of this once great nation.
A round eye’s guide into the Chinese world.
World's Ugliest Dog Contest
Spelling Bee finale
Marines train Afghan soldiers
Rolling Thunder 2013
Benghazi: The anatomy of a scandal