Police in Kenya have arrested two members of parliament and a government minister on charges of hate speech.
Lawmakers Fred Kapondi and Joshua Kutuny, and Assistant Roads Minister Wilfred Machage are accused of making inflammatory statements last week while campaigning against Kenya's proposed new constitution.
Separately Tuesday, the leader of the so-called "No" campaign, Cabinet minister William Ruto, was summoned for questioning by Kenya's National Cohesion and Integration Commission.
Political tension in Kenya appears to be rising as the August 4 referendum on the new constitution draws near. On Sunday, multiple explosions struck a Nairobi rally against the proposed charter, killing six people and wounding more than 100.
No one has claimed responsibility for the blasts. A group of Kenyan churches against the new constitution blamed them on the government, which strongly supports the constitutional reform.
On Monday, President Mwai Kibaki condemned the attack and appealed for calm, saying the government would get to the bottom of the crime.
The Cohesion and Integration Commission has urged President Kibaki and Prime Minister Raila Odinga to temporarily ban all campaigning on the August 4 referendum.
The proposed new constitution would shrink the Cabinet and set up a new system of parliament, among other changes.
Supporters say the new laws would help reduce corruption and abuses of power. The new charter is opposed by churches, in addition to some Cabinet ministers, because of its language on abortion.
The proposed reforms grew out of the 2008 power-sharing deal between Mr. Kibaki and Mr. Odinga.
The two leaders entered into a unity government after a disputed election that triggered riots and ethnic violence across Kenya. Some 1,300 people were killed before the violence was brought under control.
Some information for this report was provided by Reuters.
