A woman takes a photo as police troops guard the burnt trade union building in Odessa, Ukraine, Saturday, May 3, 2014 (Photo: AP)
Ukraine's prime minister visited the grief-stricken Black Sea port city of Odessa on Sunday, two days after 42 died in clashes between pro-Russian militants and supporters of the Kiev authorities.
Arseniy Yatsenyuk's trip was to "meet social, political, cultural and economic leaders from the Odessa region," his office said in a statement.
He was expected to hold a news conference later Sunday.
The scenic southern city of more than one million people is still reeling from Friday's horrific scenes where 38 people perished in an inferno in the centre of town after running battles.
The blaze began as pro-Moscow and pro-Kiev demonstrators traded petrol bombs after four people were killed in clashes between the opposing groups.
Earlier Sunday, Yatsenyuk vowed a "full, comprehensive and independent investigation" into the tragedy, as authorities declared two days of mourning.
The prime minister laid the blame for the deaths at the security forces.
"These security forces are inefficient and they violated the law," he told the BBC.
"The prosecutor's office is to investigate everyone -- starting with the chief of police, his deputies and every single police officer," he added.
However, he blamed pro-Russian demonstrators for "provoking" the violence.
Authorities have previously admitted the security forces were "helpless" to prevent pro-Russian militants seizing a string of towns in the east.
More than a dozen towns have fallen under rebel control and the Western-backed government in Kiev has launched what it calls an "anti-terrorism" operation to retake them.