A team of surgeons have successfully completed a complex and lengthy operation to separate two-year-old Egyptian twins born joined at the head.

"The physical separation of the conjoined twins occurred at 11:17 am (2147 IST)," Children's Medical Centre, Dallas, said in a statement.

The twins -- Ahmed and Mohamed Ibrahim -- were in stable condition. The doctors were also able to reshape the children's skulls and faces, the statement said.

"We've got to just take this a step at a time, and this has been a giant step," neurosurgeon Kenneth Shapiro of Children's Medical Centre told CNN.

"The boys right now are medically stable. We're still completing the skin closure on them," Shapiro said. "Our plans are basically to keep them in a medically induced coma for several days. Their vital signs are stable, and we don't see any sign that there have been any medical problems."

But the boys are not yet out of the woods. Dr Bradley Weprin, in charge of the follow-up care, told CNN that there is a possibility of clots leading to a stroke. "Swelling of the brain and the possible leakage of spinal fluid are also risks," he said.

Before the operation, doctors took out tissues from the inner thighs of the boys, which were used to cover the wounds created during the separation.

The operation team consisted of more than 60 people.

The World Craniofacial Foundation helped organise the operation and paid their way to Dallas.

The foundation has raised $125,000 for the separation surgery, which could cost $2 million, according to its web site. The hospital and the medical team are donating their services, the foundation said.

The twins' deformity, called craniopagus twinning, occurs in 1 in 10 million live births, according to the foundation. About 2 percent of conjoined twins are connected head-to-head.