JOHANNESBURG (AP) — Italian oil company Eni SpA said Wednesday it discovered more natural gas off the coast of Mozambique, expanding the yield of a major field off the southeast African nation that's the company's largest find.

The discovery at the Mamba North East offshore site includes at 10 least trillion cubic feet of natural gas, increasing the total yield of the Area 4 portion of the site to 70 trillion cubic feet, the company said in a statement. The newest discovery is enough natural gas to meet the needs of 5 million U.S. households for 30 years, based on average consumption.

The company said the drill site is 60 kilometers (37 miles) off the Capo Delgado coast. Eni has a 70 percent interest in the field, with Portuguese firm GalpEnergia, South Korea's KOGAS and ENH each having a 10 percent stake.

Natural gas exploration has increased in recent years in Africa, long a source for crude oil. Recent discoveries in Mozambique have made it a major regional source of liquefied natural gas.