Oil rose to the $91-a-barrel level in New York and Brent crude advanced to a 28-month high in London as protests in Egypt turned violent, prompting concern that supplies may be disrupted.

Clashes broke out yesterday in Cairo’s Tahrir Square between antigovernment protesters and supporters of President Hosni Mubarak.

About 2.5 percent of global oil production moves through Egypt via the Suez Canal and the Suez-Mediterranean Pipeline, according to Goldman Sachs.

“Everyone is watching television and the market is moving on the most recent pictures from Egypt,” said Carl Larry, president of Oil Outlooks & Opinions LLC in Houston. “The price of crude will trend higher until we get some kind of resolution to the crisis.”

The March contract was unchanged at $90.86 a barrel in electronic trading on the New York Mercantile Exchange at 10:12 a.m. Sydney time. It settled at that price yesterday after climbing as much as 1.1 percent. Futures are up 18 percent the past year.

Brent crude for March settlement increased 60 cents, or 0.6 percent, to end the session at $102.34 a barrel on the London-based ICE Futures Europe exchange yesterday. It was the highest settlement price since Sept. 26, 2008.