Greek firefighters say that at least 74 people were killed in wildfires in the country’s Attica region, which includes Athens, as a summer heatwave has increased the risk of blazes across Europe.

The fires struck two coastal resorts popular with vacationers from Greece’s capital on Monday and also resulted in 187 injuries, including 23 children, a fire department spokeswoman said in televised comments. Eleven of the injured are in critical condition, and the death toll is expected to rise further.

The fires are worse than in 2007, when record-high temperatures led to a series of blazes across the country killing at least 73 people. The casualties from this week’s wildfires were concentrated around Mati, a coastal settlement in northeast Attica, and were stoked by heavy winds, which spread the flames in the dry conditions.

“Greece is going through one of its hardest moments,” Prime Minister Alexis Tsipras said in a televised address on Tuesday, declaring a three-day period of national mourning. “Today Greece is in mourning, but we cannot allow grief to overcome us.”

The country is awaiting 60 firefighters from Cyprus and two water-bombing planes from Spain, the fire department’s spokeswoman said. “Europe will stand by our Greek friends in these difficult times. Help is on its way from several EU countries,” European Council President Donald Tusk said in a tweet.

The government held an emergency meeting on Tuesday to discuss the situation and organize compensation for damages. Tsipras spoke by phone with European Commission President Jean-Claude Juncker on Tuesday, who said that he will provide whatever means and funds are needed to combat the tragedy, according to a statement from the Greek premier’s office.

Elsewhere in Europe, Swedish authorities said the risk of fires spreading across the country will hit ” extreme” levels this week, as emergency services battled dozens of blazes that have already destroyed more than $100 million worth of forested land.

“Our thoughts are in Greece and the victims of the terrible fires,” French President Emmanuel Macron said in a tweet. “In Sweden, and in Greece, France and Europe show their solidarity and bring help.”