Authorities on the French Indian Ocean island of Mayotte on Monday began demolishing homes in a large slum in an operation against sub-standard housing and illegal migration, AFP journalists saw.

France has deployed hundreds of police officers and gendarmes in Mayotte -- the country's poorest department -- since April to prepare a major security measure called Operation Wuambushu ("Take Back" in the local language).

Diggers started destroying the sheet-metal shacks in the Talus 2 slum in the Majicavo area at around 7:30 am (0430 GMT) on Monday.

Gendarmes wielding crowbars entered the homes to check no one was inside before the destruction began, AFP journalists reported, while the electricity and water supply was cut.

The operation is due to last all week, Psylvia Dewas, the local official in charge of reducing illegal housing, told reporters.

Some 135 dwellings will be razed out of around 1,000 sub-standard homes slated for destruction on Mayotte.

The demolition of Talus 2 was originally scheduled to take place on April 25 but was suspended by a court decision. Two subsequent legal rulings then authorized the French state to proceed.

Associations have denounced Wuambushu as a "brutal" measure violating the rights of migrants, but local elected officials and many residents have supported it.

The operation initially triggered clashes between youths and security forces in Mayotte and fuelled political tensions with the Comoros, with most of the

French island's undocumented migrants coming from the neighboring archipelago.

Out of Mayotte's estimated 350,000 residents, half do not possess French nationality.