Oil prices climb as Iran tensions escalate

Oil prices are climbing again as demonstrations in Iran add to concerns that anti-government movements will keep pressure on the oil-rich Middle East for months to come.

Benchmark West Texas Intermediate for April delivery added $1.55 at $98.52 per barrel as trading opened Tuesday on the New York Mercantile Exchange. In London, Brent crude gained $2.03 at $113.83 per barrel on the ICE Futures Exchange.

Oil prices surged 13 percent last week as Libyan protesters expanded their control over the country. While the Libyan uprising continued Tuesday, Iranian authorities imprisoned opposition leaders in Tehran. Tensions are escalating in the OPEC heavyweight as groups challenge the ruling government.