Egyptians voted narrowly in favor of a constitution shaped by Islamists but opposed by other groups who fear it will divide the Arab world’s biggest nation, officials in rival camps said on Sunday after the first round of a two-stage referendum.

Next week’s second round is likely to give another “yes” vote as it includes districts seen as more sympathetic towards Islamists, analysts say, meaning the constitution would be approved.

But a close win would give Islamist President Mohamed Mursi only limited cause for celebration by showing the wide rifts in a country where he needs to build consensus on tough economic reforms.

The Muslim Brotherhood’s party, which propelled Mursi to office in a June election, said 56.5 percent backed the text.