GENEVA - Navi Pillay, the U.N. high commissioner for human rights, expressed alarm on Friday at the rising casualty toll in Egypt's deepening political turmoil and said flaws in the substance of its draft constitution and the process of preparing it were a major cause of the "disastrous situation" unfolding there that has resulted in at least six deaths.

Later Friday, early voting on the draft constitution proposed by President Mohammed Morsi was postponed. Pillay says it includes "very worrying omissions and ambiguities" that could mean it is weaker than the 1971 constitution introduced under ousted President Hosni Mubarak it is supposed to replace.

Speaking out on Egypt for the third time in a week, Pillay praised the new constitution for restricting the president to two four-year terms and for the freedom that it provides to set up civil associations and institutions simply by notifying the authorities rather than by seeking their permission.

But Pillay, in a statement, expressed dismay over the new constitution's failure to give legal standing to a range of international treaties that protect civil and political rights and forbid torture and racial or gender discrimination. That failure opens the way to national laws that may conflict with Egypt's international obligations.

Many of the new constitution's provisions refer to existing laws that are out of step with international human rights norms, Pillay said, and concentrate powers in the hands of the president that could undermine the independence of the judiciary.

The new charter, she said, guarantees equality but does not explicitly prohibit discrimination on grounds of sex, religion or origin. It guarantees freedom of religion but only specifies three faiths, Pillay added.