At least five people have died and dozens been injured in a stampede at a rally in the Kenyan capital, Nairobi.
The stampede followed two explosions, the cause of which is unknown.
The rally was organised by Christian groups opposed to a draft constitution because it retains recognition of existing Islamic courts and includes a clause on abortion.
Kenyans are due to vote on the new constitution in a referendum in August.
The Kenyan police say the explosions were small and left no debris. Police are investigating the possibility that a home-made device was detonated.
As part of a power-sharing deal to end deadly riots following elections in December 2007, it was agreed that a new constitution would be written.
The document provides for greater checks on presidential powers and more regional devolution.
However, Christian church leaders are campaigning for a "No" vote after an amendment to abolish abortion on medical grounds failed.
They also oppose the continued recognition of Islamic family courts.
The Islamic Kadhi courts - set up under British colonial rule - mainly deal with matters of marriage and inheritance for Kenya's Muslim minority.
Supporters of the new constitution deny that it opens the door to legalised abortions.