Floods devastate northern Turkey, killing at least 27, and leaving dozens missing.

“They recently pulled out a body from a grocery store, although it was supposed to have been evacuated,” Mr. Baltaci said.

The missing from the extended family in Bozkurt included 12-year-old twin girls and their grandparents, as well as two younger children and their two aunts, a relative, Fatih Karaalioglu, said by telephone.

Arzu Yucel, the mother of the twins, said the family had only been warned to move their cars to higher ground as a precaution against flooding.

Ms. Yucel, speaking in a video interview to the Demiroren news agency, said she left the apartment block next to the Ezine river where the family has apartments, on Wednesday to move the car. She became trapped by the rising waters and had to take shelter on the staircase of a nearby building.

For five hours, Ms. Yucel said, she was able to wave to her children on one of the balconies of the apartment block. But then the block collapsed.

“My eyes saw everything, we couldn’t do anything,” Ms. Yucel said.

“They told us to move the cars, not to save our lives,” she said. “I could have saved them.”

Ramazan Yucel, her husband, returning from Istanbul, arrived in the disaster area early on Thursday alongside some rescue workers, and after reaching the collapsed building by boat, worked fruitlessly to find survivors, said Mr. Karaalioglu, the relative.