Washington: International taxi-booking service Uber, which has been banned in Delhi after a woman passenger accused one of its drivers of rape, has been sued by the US city of Portland for operating its service illegally.

The city of Portland in Oregon sued Uber, three days after the California-based ride sharing service launched its widely publicised service last Friday. In its lawsuit, the city of Portland asked the court to declare that the ride provider is subject to city regulations and can't operate in until it complies with city rules.