The Afghan government has launched a major offensive against Taliban forces near the north-eastern provincial capital of Kunduz.

The provincial governor of Kunduz, Mohammed Omer Safi, says foreign jihadists trained by the so-called Islamic State, are fighting alongside the Taliban for a "bigger, modern fight".

Security forces and Taliban have been involved in a standoff for about a week after the insurgents launched an offensive on Kunduz at the end of April.