LITTLE ROCK, Ark. — An Arkansas prison spokesman told lawmakers Tuesday the deaths of five inmates at a maximum-security facility from suspected drug overdoses last week were an "unacceptable anomaly," but that correction officials have been working to reduce incidents involving a synthetic marijuana compound linked to the deaths.

Prison officials appeared before a legislative panel to discuss the deaths that occurred over four days at the Varner facility and its supermax unit. The Department of Correction has said cause of death hasn't been determined, but that the compound K2 may have been involved.

"What happened last week was an anomaly and it was an anomaly that we will not tolerate becoming the norm," department spokesman and legislative liaison Solomon Graves told lawmakers.

Arkansas had 13 deaths from K2 last year, and six so far this year — not counting the five deaths last week. Graves said there were 1,136 incidents involving K2 at state prisons last year — ranging from the drug being found to overdoses— and 534 so far this year. If that trend continues, Arkansas will have 712 incidents this year — a 37 percent decrease.

"That is 712 incidents too many if we hit that number, but what that does show is we are implementing policies, we are implementing programs and we are implementing reforms that are working," he said.

Those changes have included restrictions on mail to inmates and expanded use of body scanners.

Graves told the panel that the department will also ask lawmakers to increase the penalties for K2 in prisons and to support efforts at the federal level to jam the signals of contraband cellphones at prisons.

A lawmaker who called for the hearing on the deaths said the department's comments didn't allay her concerns about its ability to combat K2 use among inmates.

"There was nothing that was said to me today to suggest that we have any kind of control any more than we did, say, yesterday on what's going on," Democratic state Sen. Joyce Elliott told reporters after the hearing. "I'm still greatly concerned."