MOSCOW. April 15 (Interfax) - Russia's human rights ombudsman said he had the impression "there had been instances of serious exceeding" by police of their powers in dispersing an opposition demonstration in St. Petersburg on Sunday.

"What I was able to see on TV screens gave me the impression there had been instances of serious exceeding of their duties by some members of the personnel of law enforcement services," Vladimir Lukin told Interfax.

"I will be ready to give careful consideration to complaints from persons who were hurt and, if I consider them justified, I will insistently ask the Prosecutor General's Office to institute criminal proceedings, proceedings that I will uphold in court," he said.

"I could see that blood had been shed on the streets. Fortunately there were no irreversible incidents," Lukin said.

It is the duty of the police "to guarantee the peaceful and secure character of rallies and processions, and they must not take any action that threatens the lives or health of people, both participants in such events and passersby," he said.

"It is exactly this that is their constitutional duty," he added.