An Afghan official says the military has sent reinforcements to a northern province to fight Taliban insurgents closing in on the provincial capital.

Interior Ministry spokesman Sediq Sediqqi says a major operation is underway in Kunduz province, where fighting continued for the fourth day Tuesday.

He says a Taliban commander and 27 of his fighters were killed Monday night in the province's Imam Sahib district, near the capital, also called Kunduz.

The fighting began over the weekend, when a large number of insurgents attacked police and army check points around Kunduz city. The Taliban launched their spring offensive on Friday.

President Ashraf Ghani delayed a state visit to India by several hours on Monday to consult with U.S. Gen. John Campbell, commander of NATO forces in Afghanistan, on the matter.