Hennepin County Sheriff Rich Stanek announced Friday that law enforcement officials seized 18 guns -- an unusually high number -- during one week this month while executing search warrants.

Stanek said the guns were found between May 6 and 13 in three locations in Minneapolis and one in Richfield.

Stanek said the Hennepin County Violent Offender Task Force, which includes Brooklyn Park and Golden Valley police, assisted in the seizures. The force typically confiscates less than a half-dozen guns a week.

The firearms were seized because convicted felons had them or because they were used in crimes.

The seizures come during a period when Minneapolis and Hennepin County have seen decreases in violent crimes. In 2008, violent crimes decreased by 12 percent from the previous year.

"We're proud of the hard work of deputies and police officers throughout the county for helping to reduce violent crime," Stanek said. "However, the seizure of all these guns serve as a reminder that we must remain vigilant."

Since its inception in 2007, the task force has seized 163 firearms. It seized 33 firearms so far this year, and the Sheriff's Office's narcotics unit has seized 34.

During a news conference, Stanek pointed to a table and noted that several of the guns were semiautomatic handguns or sawed-off shotguns, with few "old-fashioned" weapons.

"You don't go hunting with these," he said. "They're used to kill people."