As the death toll from Greek wildfires rose to at least 74 on Tuesday, survivors of one huge blaze near the country's capital recounted how families fled to the sea to escape advancing flames.

Residents scrambled to the water's edge as the country's worst blaze in more than a decade swept through the coastal resort of Mati, near Rafina, 18 miles east of Athens. Hundreds were rescued by passing boats, but others found their way blocked by smoke and flames.

A second blaze near the resort of Kineta, about 30 miles west of Athens, was fanned by gale-force winds.

Fire service spokeswoman Stavroula Malliri said that at least 74 people had died as of Tuesday afternoon and that 164 adults and 23 children being treated in hospitals for injuries.

Xeni Dimitriou, the chief criminal prosecutor at the Greek supreme court, ordered an investigation as complaints circulated that the government was slow to respond and that there appeared to have been no evacuation plan, the Athens newspaper E Kathimerini reported.

In Mati, many victims died after becoming trapped in their cars, photographer Giorgos Moutafis wrote on Facebook, while others drowned.

Nikos Economopoulos, the head of Greece's Red Cross, told Skai TV: "I was briefed by a rescuer that he saw the shocking picture of 26 people tightly huddled in a field some [100 feet] from the beach. They had tried to find an escape route, but unfortunately these people and their kids didn't make it in time."

Many victims appeared to be hugging when they died, he added. One of the youngest was thought to be 6 months old.

Panagiotis Dagalos told Reuters that he ran to the beach carrying in search of his wife, who he believes was killed.

"No, I didn't turn my head back. Nothing," he said. "I was running towards the sea. I was — I had memorized the track because [the] last day we had swimming at the beach, so I knew where to go."

Coast guard and other vessels rescued 696 people who had fled to beaches. Boats plucked another 19 people from the sea.

Andreaas Passios, a local resident, said: "I grabbed a beach towel. It saved my life. I soaked it, grabbed my wife, and we ran to the sea. It was unbelievable. Gas canisters were exploding. Burning pine cones were flying everywhere."

A closed road stops cars during a wildfire in Kineta, Greece, on Monday. Valerie Gache / AFP - Getty Images

Nikos Stavrinidis said he ran to the sea with his wife and friends. "We had to swim out because of the smoke, but we couldn't see where anything was," he told The Associated Press.

Six people were in his group: Stavrinidis, his wife and some of her friends. They swam farther out to escape the smoke, but they began to be carried away by the wind and the current. They lost sight of the shore and became disoriented. "We couldn't see anything," Stavrinidis said.

"We didn't all make it," he said. One of the women in his group and one woman's son drowned.

"What upsets me and what I will carry in my heart is that it is terrible to see the person next to you drowning and not be able to help him. You can't. That's the only tragic thing," he said, his voice breaking. "That will stay with me."

Some parts of Mati were still smoldering with white smoke early in the day. Burned-out cars were scattered outside gated compounds where three- and four-story buildings bore signs of fire damage.

Prime Minister Alexis Tsipras declared a three-day period of national mourning for the victims.

Wildfires are not uncommon in Greece, and a relatively dry winter helped create current tinder-box conditions. It was not immediately clear what ignited the fires.

In Kineta, motorist Giannis Labropoulos said he and his wife were "terrified" to see flames licking the sides of the main highway between Patras and Athens.

"In less than a minute, we saw smoke covering the road," he told Euronews. "And then all of a sudden, the fire really covered everything. ... I stopped [recording video] in order to be able to see in front."

Heavy rain is forecast across southern Greece on Wednesday.

It is the deadliest fire season to hit Greece in more than a decade. More than 60 people were killed in 2007 when huge fires swept across the southern Peloponnese region.