NAIROBI, July 19 (Xinhuanet) -- Kenyan police Tuesday heightened security in the capital Nairobi after banning demonstrations outside the parliament building where lawmakers are due to debate a draft constitution.

    Anti-riot police backed up by water cannon have sealed off the parliament area and are patrolling the streets to keep off the protesters demanding a referendum on a new draft constitution which would limit the president's powers.

    Security around the parliament is extremely tight and those entering the building were frisked before entry.

    The police have outlawed the planned protest on parliament, saying the march planned by civil society organizations including the opposition lawmakers will cause chaos and mayhem.

    The protesters fear the legislators will amend the draft leaving the president's authority largely intact.

    The ruling coalition has been accused of mutilating the draft legislation which was initially agreed after many months of debate.

    Kenyans are due to vote in a referendum on the new constitution in October.

    Prior to the vote, the legislators are expected to discuss and vote on the constitution's draft text this week.

    The Liberal Democratic Party which is part of the ruling National Rainbow Coalition but is at the forefront of attempts to get a new constitution, after its leader, Raila Odinga, was promised the new post of prime minister, has teamed up with the opposition Kenya African National Union (KANU) to press for the draft which recommended that most powers go to a new and powerful post of prime minister.

    Delegates have spent months drafting a new constitution but this has not yet been implemented.

    Previously, a two-thirds majority was needed to make changes tothe constitution. But now changes can be made with a simple majority, which led KANU leader Uhuru Kenyatta to accuse President Mwai Kibaki of reneging on his promise to give Kenyans a people-driven constitution.

    President Kibaki's National Rainbow Coalition came to power in 2002 on a pledge for constitutional change.

    "We are not going to participate whatsoever because he is trying to use a clique of his friends to amend the constitution through the backdoor," Kenyatta said.

    "The parliament has usurped the role of the Kenyan people. We shall join the other Kenyans in making our protests in whichever forum," Kenyatta told reporters.

    The protesters argue that the move to call for mass action was a culmination of spirited efforts to push the government to allow all stakeholders to take part in the review process. Enditem