The newspaper said it obtained internal documents put together for congressional and Defense Department investigations on the work done by contractors. The documents show that many soldiers have suffered non-lethal shocks in their barracks, the report said.

The work was done by KBR, one of the largest military contractors and a former subsidiary of Halliburton.

Staff Sgt. Ryan Maseth died from an electrical shock while taking a shower in January. The death focused attention on poor wiring.

The internal documents show there were 283 electrical fires in the second half of 2006. Two soldiers died in one fire in 2006.

One report said KBR self-reported a "systemic" problem with electrical work at bases in Iraq.

The Times said neither the Pentagon nor KBR would comment on the details of the reports.