The European Union Observation Mission to Nigeria says soldiers barred them from monitoring elections in Rivers State.
The observers made the allegation in their preliminary report in Abuja on Monday.
Addressing journalists, the Chief Observer, Maria Arena, noted that they came to Nigeria on the invitation of INEC to monitor the elections and make recommendations.
Arena, who is a member of the EU Parliament, however, faulted the elections.
She said, “Observers, including EU observers, were denied access to collation centres in Rivers, apparently by military personnel. This lack of access for observers compromises transparency and trust in the process.
“In Rivers, INEC suspended until further notice the elections due to violence in polling units and collation centres, staff being taken hostage and election materials, including results sheets, seized or destroyed by unauthorised persons.
“There is no doubt that the electoral process there was severely compromised.”
Arena lamented the violence, underage voting and vote-buying that marred the governorship and House of Assembly elections in some states.
She said the EU deployed 73 observers following voting, counting and the collation of results in 22 states.
The chief observer said they monitored 223 polling units in 81 collation centres.
Arena added, “Although election operations improved, the elections were also marked by an overall low turnout and violence, including against election officials and voters.
“However, at eight polling units observed, we saw indications of vote-buying. Eight cases of obvious underage voting were also observed. Our observers saw that the counting of ballots transparent overall.
“Positively, in almost all cases, party agents received copies of the result forms, although they were often not displayed. The environment for these elections has been difficult, with cases of violence and intimidation, including attacks on election administration officials.”