POLICE believe an organised criminal gang is behind the cannabis-growing factories recently discovered on housing estates across Oxford.

The news comes after almost 400 cannabis plants, with a potential street value of tens of thousands of pounds, were found when police raided two Oxford properties on Wednesday morning.

The swoops are linked to drugs raids carried out in recent weeks at properties in East Oxford in Warwick Street and Fairacres Close in April, and Aston Street in May.

On each occasion, police found a professional hydroponics set-up. The houses had been converted to incorporate metallic ventilation pipes and all had only very basic home comforts.

The dawn raids in Rose Hill, involving two teams of eight police officers, happened simultaneously at 6.30am at Lenthall Road (code-named Operation Brummie), and Rivermead Road (code-named Operation Bengal).

A 21-year-old Vietnamese man was found inside the Rivermead Road house and arrested and a 19-year-old Vietnamese man was later arrested outside the Lenthall Road house after he pulled up in a red Vauxhall Astra about 30 minutes after police entered the property.

Katharine Miles, 33, and Jenni Kornell, 31, who live next door to the raided property in Rivermead Road, were woken by the noise of the police banging the door down. Miss Miles said: "I never suspected anything like this was going on."

The 21-year-old occupant of the Rivermead Road property had to be taken to hospital following the raid after he received cuts to his foot from broken glass.