On Saturday, workers at the Woman's Health Center in St. Petersburg and the National Women's Health Services in Clearwater on the west coast of the state called police to report that someone had drilled small holes into the buildings' doors and then sprayed a noxious substance inside.
Investigators determined that the substance was butyric acid, which had been used in similar attacks at five clinics in Miami on Thursday and three attacks on clinics in Orlando and the Daytona Beach area last weekend.
"We've had a total of 10 in exactly a week," said Ray Velboom, special agent and intelligence supervisor for the Florida Department of Law Enforcement in Tallahassee.
"There's a good chance they are all related, but we have not been able to prove that forensically," he said. He said they had had some leads, but declined to discuss them. ``There's a couple, but nothing we can really discuss.''
Police were called on Saturday about the acid attacks at about 9 a.m. EDT, but they said they could not immediately determine whether they had taken place early Saturday morning or overnight Friday.
The latest attacks were nearly identical to attacks reported last Friday on two clinics in the Daytona Beach area and one in Orlando. And Thursday, five clinics in the Miami area -- three in the city and two in suburbs -- were splashed with butyric acid, some while clinic workers were inside.
Butyric acid is a corrosive industrial chemical that smells like vomit, irritates the eyes and skin and can be fatal in large doses.
All of the attacks came within days of "Operation Pushback," eight days of anti-abortion demonstrations that Operation Rescue, the national anti-abortion group known for its clinic protests, has said it would stage in the Orlando area beginning May 31.
Police said there was no reason to believe that Operation Rescue was involved in the attacks. And representatives of well-known anti-abortion organizations have denied any involvement.
A local television station reported that investigators in Miami had seized a burgundy rental car that reeked of butyric acid, and might have been connected to the attacks. The television station reported that police took fingerprints and an unidentified bag of objects from the car.
By Patricia Zengerle