MEDINACELI, Spain: Millions of people gathered across Spain, Portugal, Iceland and other parts of Europe on August 12 to watch a rare total solar eclipse.

The event occurred when the sun, moon, and Earth lined up, causing the moon to block the sun for a short time, completely plunging parts of the region into darkness.

In Spain, large crowds filled cities and towns under clear skies as people searched for the best places to watch the eclipse. Many arrived with lawn chairs and umbrellas and waited excitedly for the event to begin in the early evening. As the daylight slowly faded and then disappeared more quickly, crowds applauded and cheered. It was Spain's first total solar eclipse in more than 100 years.

Apart from northern and central Spain and Portugal in mainland Europe, the eclipse also passed over parts of Greenland and Iceland.

The period of total darkness, known as totality, occurred when the moon completely covered the sun. It was expected to last for less than two and a half minutes, with the longest period occurring off the western coast of Iceland. When the eclipse reached a small area of Portugal and then Spain shortly before sunset, totality had shortened to around one minute. The total eclipse then moved over the Mediterranean.

Spanish authorities expected the event to attract at least 500,000 additional visitors. Hotel demand increased sharply in cities along the eclipse's path, including A Coruña, Bilbao and Santiago de Compostela.

The event took place during a period of extremely hot weather and ongoing wildfires in Spain, prompting authorities to launch a major public safety operation.

Temperatures rose above 35 degrees Celsius (95 degrees Fahrenheit) in many parts of Spain where people gathered to watch the eclipse. Authorities established around 350 official viewing locations across the country's sparsely populated interior. The Interior Ministry said more than 33,500 police and other law enforcement officers were deployed at viewing areas and key access points.

The eclipse came only weeks after Spain suffered its most destructive wildfire on record. The blaze burned around 500 square kilometers (193 square miles) and forced tens of thousands of people to leave their homes in Ávila, in central Spain. Several smaller fires were still burning in other parts of southern and central Spain.

In Reykjavik, Iceland, cloudy and rainy weather did not stop hundreds of people from gathering outside the famous Hallgrímskirkja church. Many wore bright raincoats as they waited for the sky to darken.

As the rain became heavier, the sun became barely visible before darkness suddenly spread across the area. The only lights clearly visible came from mobile phones held above the crowd.

People cheered as the sky darkened and celebrated even more loudly when daylight began to return. Many then quickly left the square rather than staying to watch the rest of the partial eclipse.

Experts stressed that special eclipse glasses were necessary to protect the eyes, even when only a small part of the sun was visible. The glasses contain special filters that block harmful solar radiation.

For months, shops, supermarkets, museums and planetariums across Spain had sold or handed out eclipse glasses. Many pharmacies had run out of supplies before the event.

In Britain, where more than 90 percent of the sun was expected to be covered, people gathered in hilltop parks and other open areas to get the best possible view. The event was described as the country's most impressive eclipse since 1999.

In Greenwich Park, which offers views across the River Thames towards central London, the sky took on an unusual grey hue. A thin crescent of sunlight appeared above the moon, creating the appearance of a bright hat sitting on top of it.