Ouagadougou, Oct 30 (IANS/EFE): Hundreds of protesters Thursday stormed Burkina Faso's parliament and burned one of its halls to prevent a vote on a constitutional amendment that would allow President Blaise Compaore to stay in office.

Riot police used tear gas in an attempt to stop the assault but finally were forced to withdraw.

The security forces had blocked the entrances leading to the parliament with armoured cars in anticipation of the protest.

During the assault, several explosions could be heard in the distance.

Compaore, who has been in power since 1987 after staging a coup, can stand for re-election in 2015 if the amendment is passed.

Opposition leader Zephirin Diabre had called for a "national mobilisation" against the amendment, which is expected to be passed in parliament, where Compaore's Congress for Democracy party has a majority.

The protests began two days ago, when thousands marched in Ouagadougou shouting "Twenty-seven years is enough".