Image copyright Aerovironment Inc Image caption The Puma is a handheld unmanned aerial vehicle designed for the US military

The US Federal Aviation Administration (FAA) has granted its first commercial drone licence over US land to British oil giant BP and unmanned aerial vehicle firm AeroVironment.

The drones will patrol pipelines, roads, and equipment in Prudhoe Bay, Alaska - the largest oil field in North America.

The first drone flight took place on Sunday, the firms said.

It featured a small, hand-launched vehicle called the Puma AE.

It is a small unmanned aircraft about 4.5ft (1.4m) long with a wingspan of 9ft (2.7m).

The Puma was initially designed for military use, but has been adapted to fit BP's needs, according to AeroVironment.

"This is an important achievement for our joint team and for the industry in demonstrating the safe and effective use of our proven [unmanned aerial system] technology for commercial applications," said AeroVironment chief executive Tim Conver in a statement.

The firm has already been using its Puma drone in the area since September 2013 to offer 3D road mapping services, as well as environmental monitoring, as part of a pilot programme with the University of Alaska.

Image copyright Aerovironment INc Image caption AeroVironment, a supplier of drones to the US military, also has pilot programmes with police departments

Loosening up

"These surveys on Alaska's North Slope are another important step toward broader commercial use of unmanned aircraft," said US Transportation Secretary Anthony Foxx in a statement.

This is the latest effort by the FAA to loosen restrictions on drone activity.

Currently, commercial drone flights in the US are banned, although the FAA is set to release regulations allowing for some uses by 2015.

Businesses from agriculture to film have been lobbying the agency to loosen restrictions ahead of that deadline, particularly as other countries around the world allow for unmanned aerial flights.

However, the US has some of the most congested airspace in the world, and the FAA has said it must weigh the commercial demands carefully against safety and security concerns.