In a statement read over state television, presidential office head Ahmed Hussein Khudeir said it was "important that Baghdad glow with light" to make life easier "for people in these difficult conditions."

"All individuals, ministries, state administrations and private firms that have electric generators must turn them on at night when the power is cut," he said.

Electricity returned late Friday in parts of central Baghdad, with street lamps again glowing in the district surrounding the main presidential palace, a frequent target of the US-led coalition.

Private homes and businesses in the area also had their power restored. It was unclear to what extent other areas of the capital were back on line.

The electricity had been out for nearly 24 hours in the city of five million, leaving residents scrambling to buy the last remaining generators in the capital at exorbitant prices and compromising the water supply.

The US Defense Department said it had not targeted the power grid and could not explain why the power had been cut.

The International Committee of the Red Cross (ICRC) said Friday that it was alarmed by the impact the blackout could have on Baghdad hospitals as US troops massed at the city's doorstep.

"The total interruption of electricity on the first day of the battle of Baghdad could lead to a catastrophic situation in the hospitals," Peter Tarbula, medical coordinator of the ICRC in Baghdad, told AFP.

The some 30 hospitals in the capital would have to rely on generators and "they will not last for long".

"If, after the electricity, the water is cut in the capital, it will be a humanitarian catastrophe," he said.

WAR.WIRE