Thijs Berman, head of the EU election assessment team told reporters in Kabul that issues have been noted in 6000 polling stations.
Berman further added that the information has been received from the electoral teams and independent election commission.
He called for an in depth review of the electoral fraud claims and said the number of polling stations with issues is relatively higher since 23,000 polling stations were open during the elections day.
Berman said his team also increased monitoring of the election process and they remain committed to observe the process precisely.
The European election assessment team consisted of six observers who are were deployed in Kabul, Balkh and Herat provinces.
According to Berman, the European Union has met with the presidential contenders and electoral bodies in a bid to resolve the current impasse.
Berman also added that the European Union has remain neutral in election process and hoped that the necessarysteps will be taken to clean the fraudulent votes.