Mayor Mike McGinn apologized Wednesday after some Occupy Seattle protesters, including an 84-year-old woman, were pepper sprayed during a march Tuesday night.

Six people were arrested after police said they blocked downtown traffic and ignored orders to disperse. Dorli Rainey, an elderly local activist, was among those hit by pepper spray. A picture of Rainey, who was not arrested, quickly went viral.

McGinn said in a Wednesday afternoon statement that he had spoken with Rainey, and had also directed police leadership to review the incident.

"To those engaged in peaceful protest, I am sorry that you were pepper sprayed," he said. "I also called in Seattle Police Chief John Diaz and the command staff to review the actions of last night. They agreed that this was not their preferred outcome."

In a statement Wednesday, Occupy Seattle said McGinn's apology "does not go far enough" to ensure demonstrators are safe and said the mayor does not hold the police department accountable for "misuse" of force.

The mayor said police officers are facing difficult circumstances trying to maintain order the many Occupy protests throughout the city. He said police are developing procedures to make sure there are enough commanders on the scene at future protests.

McGinn referenced the 1999 World Trade Organization protests in Seattle, at which there were mass arrests, a nighttime curfew in parts of the city and the deployment of National Guard troops to maintain order, as well as 2001 riot during Mardi Gras celebrations that left a young man dead.

"In both instances insufficient attention and preparation led to severe public safety issues," McGinn said.

McGinn said "tensions appear to be getting higher" as the local Occupy movement stretches into its sixth week.

Protesters initially pitched tents at a downtown park in a heavily-trafficked shopping district. But McGinn told them they couldn't stay overnight on city property and late last month they moved to a community college east of downtown. However college officials there say the encampment is disruptive and are trying to get it to leave.

McGinn asked local protesters to work with the city to ensure that marches don't become violent.

Occupy Seattle responded by saying they do work with the city, and said they had alerted police of their march and the route.

However, organizers also said they did not obtain a permit to march because the demonstration was put together rapidly.