An Afghan government minister has survived a bomb attack on his motorcade in northern Afghanistan, the second assault on a high-profile politician in two days, but two of his bodyguards have been wounded.

Higher Education Minister Obaidullah Obaid was travelling from Baghlan to Kunduz province when one of the cars in his convoy hit a roadside bomb on a highway outside Baghlan city.

The provincial governor of Baghlan Munshi Majid, who was in the same motorcade, said: "The minister is safe. Two policemen were wounded in the bomb attack."

Sunday's attack came a day after a suicide bomber blew himself up at a wedding reception in Samangan province, killing a top Afghan official and 22 others.

On Friday, a car bomb killed a regional head of women's affairs in the east of the country, a sign that insurgents have spread their reach from their traditional strongholds in southern and eastern areas of Afghanistan to northern parts of the country once considered relatively safe.

Homemade bombs are by far the most lethal weapons deployed by insurgents and remain the single biggest killer of civilians, as well as foreign and Afghan troops.

Violence in Afghanistan is at its fiercest since US troops overthrew the Taliban government in 2001.