People and their pets should not swim or splash in the Schuylkill or the Wissahickon Creek because of a fish kill detected in Montgomery County, city and state authorities said last night.

People also are being advised not to eat fish from those waters, nor to boat or row there.

"As a precautionary measure, the city has issued a health advisory," Managing Director Pedro Ramos said last night at a news conference, flanked by members of the state Department of Environmental Protection, the city Water Department, and the Fairmount Park Commission.

"We're urging people not to swim, fish or boat in the Wissahickon and in the Schuylkill in the area below where it meets the Wissahickon," all the way to the Delaware River, he said, standing in front of the Municipal Services Building.

The advisory does not affect home drinking or bathing water, Ramos said.

"It is important to know drinking the city water is safe," he said.

The fish kill and a "high level of toxicity" were detected in the Wissahickon Creek by the Upper Gwynedd Township Wastewater Treatment Facility, where the fish kill originated, Wednesday afternoon, Ramos said. City officials notified Wednesday night first reviewed the information before putting out the warning.

Officials last night did not know how many fish had died. The cause of the fish kill was still being investigated by the state DEP and the city Water Department.

Debra McCarty, deputy commissioner for the city's Water Department, said the extent of the fish kill so far had been two miles downstream from the treatment plant.

"Different varieties of fish have shown stress and died," she said.

The Montgomery County treatment plant is 10 miles from the city line and 18 miles from the closest city water-treatment plant, Ramos said.

Ramos said the city had taken precautions by closing the city's raw water intakes at its Queen Lane Water Treatment Plant in East Falls and at the Belmont Water Treatment Plant farther downstream.

He said he did not know how long the advisory would be in effect. As of now, the city does not plan to assess penalties for violating the warning.

City and state officials are scheduled to meet today and review the latest laboratory results.

Last night, Ramos said the fate of the Schuylkill Navy Regatta, scheduled for tomorrow, and a triathlon next weekend were still uncertain.

The 148th annual Schuylkill Navy Regatta is expected to bring in 40 clubs and 600 athletes.

Clete Graham, commodore of the Schuylkill Navy, said last night: "We just have to wait and see what they say. As rowers, we hope never to swim. It's going to depend on what happens in the next 24 hours. If they say we can't row, we won't row. If they issue a caution, we'll have to see."

Many athletes plan to compete in the Philadelphia Insurance Triathlon the following weekend, in which they are to swim across the river.

Brian Colgan, trustee and past president of the Vesper Boat Club on Boathouse Row, had not heard about the warning.

"We were rowing out today, and water was splashing on my face - yuck," he said.

Colgan, 47, said he was not worried.

"I would just advise people not to splash water on themselves while rowing," Colgan said.

The city will provide updates at http://www.phillyrivercast.org/. People also can call the city Water Department at 215-685-6300.