A massive roadside bomb has killed at least 18 people on their way to a wedding in northern Afghanistan. At least 15 others have been wounded in what a BBC correspondent called one of the worst such attacks in the country for some time. A minibus was carrying men, women and children to the wedding in the Dawlatabad district of Balkh province when it was struck by the bomb, the BBC reported. It is not clear whether they were the intended target. No-one has yet claimed responsibility. Officials say they expect the number of dead to increase. Northern Afghanistan has generally been one of the safest parts of the country since the US-led invasion in 2001 while Balkh has seen an increase in Taliban activity in recent years, which Nato forces – despite their extra numbers – have been unable to suppress.