"There was a suicide attack at the army recruitment center in Kunduz city," said Mehboubullah Sayedi, a spokesman for the governor of Kunduz province.

"The preliminary information we have suggests that 33 people were killed and another 42 were wounded."

The spokesman added: "Most of those killed were volunteers who wanted to join the army."

The attack came four days after the provincial police chief of Kunduz, Abdul Rahman Sayedkhili, was killed by a suicide bomber on a motorcycle in the city along with four other people. That attack was claimed by the Taliban.

Once relatively quiet, Kunduz and some other parts of northern Afghanistan have witnessed increased violence in recent months.