World crude oil prices hovered above 72 dollars Monday amid concerns over the Iranian nuclear issue.

New York's main contract, light sweet crude for delivery in July, added 27 cents to close at 72.60 dollars a barrel.

In London, Brent North Sea crude for July delivery advanced by 34 cents to 71.37 dollars a barrel.

Iran's Supreme Leader Ayatollah Ali Khamenei warned on Sunday that oil flow in the Gulf region, which supplies 20 percent of the world's oil, would be affected in its dispute with the West over its nuclear enrichment program.

The United States said on Monday that Iran should be given time to consider incentives from major powers in exchange for curbing its nuclear program.

European Union foreign policy chief Javier Solana is to deliver a package of incentives and disincentives to Iran this week in a bid to make a settlement of Iran's nuclear crisis.

Gunmen kidnapped eight foreign workers on an oil rig off the coast of Nigeria Thursday night, posing a new threat to the oil output of the west African country, the biggest oil exporter in the continent. However, armed militants on Sunday freed the eight workers after oil companies operating in Nigeria agreed to distribute more wealth to local communities.

Source: Xinhua