Police used teargas and rubber bullets against stone-throwing, stick-wielding opposition activists.
Witnesses said police were also injured in the clashes in Shyamoli, a residential area of Dhaka
The alliance said the blockade was aimed at forcing Iajuddin Ahmed, the Bangladesh president, to step down as head of the interim government and force the election commission to announce new poll schedules.
The opposition says Ahmed and the election commissioners are favouring a rival alliance led by Begum Khaleda Zia.
Ahmed, in a statement late on Saturday, said there was no way he or the election commission would delay the ballot because of constitutional constraints.
In a statement, the European Union has said it was "deeply concerned and disappointed by recent developments relating to the parliamentary elections in Bangladesh, in particular the decision by major parties to withdraw from participating on January 22".