Two-year-old triplets from New Zealand were among 19 people killed in the fire that broke out in Qatar’s Villaggio mall on Monday, reports said.

The blaze, which trapped children and staff in the Gympanzee daycare centre and nursery, led to the deaths of seven young girls, six young boys, four teachers and two members of the Civil Defence team fighting the fire, a report in Gulf Times newspaper said.

The cause of the fire is still unknown. It broke out at about 11am and was believed to have been started in the daycare centre itself or one of the surrounding shops. Investigations are underway.

Some of the victims died as rescuers struggled to reach the child care centre at the mall in Doha, according to Qatar’s Minister of State for Interior Affairs Sheikh Abdullah bin Nasser Al Thani.

“We tried our best, but when we got there, the children were trapped inside. We are very sorry for what happened. We tried as much as we could to save these people,” Sheikh Abdullah told reporters.

New Zealand Prime Minister John Key and others offered condolences Tuesday to the parents whose 2-year-old triplets died.

Four of the children killed were Spanish citizens, the Spanish Foreign Ministry said. It did not identify the children.

Also, a 3-year-old French child was among the victims, the deputy minister for overseas French citizens, Yamina Benguigui, said in a statement.

Four teachers and two civil defence officials were also among the dead, the Qatari ministry said on its official Twitter page.

At least three of the nursery teachers were from the Philippines and died of smoke inhalation, Philippine Foreign Affairs spokesman Raul Hernandez said in Manila.

Another 17 people were injured, including four children, according to authorities. Most of those hurt were rescuers responding to the blaze.

Witnesses earlier reported thick black smoke pouring from the ritzy mall around midday. Amateur photos and videos posted online showed firefighters rescuing victims by climbing on the roof. The cause of the fire is under investigation.

Thick smoke and heat hindered rescue efforts, as did a lack of floor plans and malfunctioning sprinkler systems, the ministry said on Twitter.

Sheik Abdullah said all buildings in the country abide by safety requirements, but a special committee will nonetheless be set up to monitor building safety standards.

The Villaggio opened in 2006 and is one of Qatar’s most popular shopping and amusement destinations. Retailers include many well-known Western brands, such as Foot Locker, Pizza Hut, Starbucks and British department store Marks & Spencer, according to the mall’s website.

The Villaggio includes an ice skating rink, theme park, movie theatre and indoor Venice-style gondola rides.