"We strongly condemn this reprehensible act," State Department spokesman Ned Price said in a statement, citing "credible reports that security forces denied medical personnel access to the victims of this terrible attack."

"Denying victims urgently needed medical care is heinous and absolutely unacceptable," said the statement, urging the Ethiopian authorities to "ensure full and unhindered medical access to the victims immediately."

Survivors and emergency workers gave accounts of dozens of people killed or wounded when bombs fell Tuesday midday on Togoga, a market town northwest of Tigray's regional capital Mekele.

The carnage unfolded as ballot-counting was underway across much of the rest of Ethiopia following Monday's national election, but the seven-month conflict in Tigray prevented any voting there.

The United States echoed the United Nations in calling for "an urgent and independent investigation."

The State Department also urged "remedial action, to hold those responsible for this attack accountable," as well as "an immediate ceasefire in Tigray, unhindered humanitarian access, and protection for civilians."