Hurricane Agatha left at least 11 people dead and 20 missing in southern Mexico, where heavy rains caused flooding and mudslides, the governor of the southern state of Oaxaca said Tuesday.

Governor Alejando Murat said rivers overflowed their banks and swept away people in homes, while other victims were buried under mud and rocks.

"There were fundamentally two reasons" for the deaths, Murat told local media. "There were rivers that overflowed, and on the other hand, and the most serious part, were landslides," he added.

Murat said the deaths appeared to be concentrated in a number of small towns in the mountains, just inland from the coast. But he said there were also reports of three children missing near the resort of Huatulco.

Agatha made history as the strongest hurricane ever recorded to come ashore in May during the eastern Pacific hurricane season.

It made landfall Monday afternoon on a sparsely populated stretch of small beach towns and fishing villages in Oaxaca.

It was a strong Category 2 hurricane, with maximum sustained winds of 105 mph (168.98 kph), but it quickly lost power moving inland over the mountainous interior. Remnants of Agatha were moving northeast Tuesday into Veracruz state.

Murat said power had been restored to some communities near the coast, but that some bridges had been washed out and mudslides blocked a number of highways.

San Isidro del Palmar, only a couple of miles inland from the coast, was swamped by the Tonameca river that flows through town.

Residents waded through neck-deep water to salvage what items they could from their homes, walking gingerly with piles of clothing atop their heads and religious figures in their arms.

Argeo Aquino, who has lived in the town his whole life, said he could recall only two other occasions when he saw such flooding.

"The houses are totally flooded, so they are getting everything out,” Aquino said Monday as he watched his neighbors. "There are stores, houses. More than anything else, we have to try to save all the good material, because everything else is going to be washed away," he explained.

The Tonameca's brown waters reached the windows of parked cars and the minibuses used for local transportation.

Nearby, heavy rain and high winds lashed the beach town of Zipolite, known for its clothing-optional beach and bohemian vibe. The wind howled for about six hours on Monday, aid Silvia Ranfagni, manager of the Casa Kalmar hotel in Zipolite.

"The sound of the wind was really loud, high-pitched,” said Ranfagni. "It started at 1 p.m. when the telephone coverage went out and it didn't calm down until 7:30 p.m.”

"A lot of trees were down, roads washed out,” she said. "A lot of metal and thatched roofs were blown off.”

Agatha formed on Sunday and quickly gained power. It was the strongest hurricane on record to make landfall in May in the eastern Pacific, said Jeff Masters, a meteorologist with Yale Climate Connections and the founder of Weather Underground.