The mayor of Toledo, Ohio, says new tests show that toxins are still in the city's water supply.
The readings come two days after 400,000 people in northwestern Ohio and southeastern Michigan were told to avoid drinking tap water.
Mayor D. Michael Collins said early Monday that most of the results were acceptable but some concerns remain.
Toledo officials issued the water warning in Ohio's fourth-largest city early Saturday after tests revealed the presence of a toxin likely from algae on Lake Erie.
The Ohio National Guard and other state agencies have been delivering pallets of bottled water to city and operating water purification systems to make more drinkable water.
Explore further: 400,000 in US city told not to drink tap water