Sheikh Mohammed bin Rashid and Sheikh Mohammed bin Zayed offered their condolences to the Al Sreidi family over the deaths of seven Emirati children in a fire that broke out in their home in Fujairah on Monday morning.
Police said the children were suffocated in their sleep by the smoke.
On Monday, the Vice President and Ruler of Dubai tweeted a message to the family saying "a casualty on our children is a casualty on our country".
"We are shocked today by the death of seven of our children in a house fire. Our condolences to the people of the UAE on the deaths of [the children]," he said.
The Crown Prince of Abu Dhabi and Deputy Supreme Commander of the Armed Forces also tweeted a message to the family reading, "our hearts go out to the family and relatives.
"We offer them our heartfelt condolences," he said, calling for God to grant mercy on the children's souls and grant the family patience and solace.
Fujairah police were alerted to the fire in Roll Dhadna at 5.40am and immediately dispatched patrols, ambulances and firefighters to the site.
"The operation room received a call at 5.40am from the mother saying a fire broke out in the living room of her house while her kids were asleep," said Maj Dr Saeed Al Hassani, head of the media department at Fujairah Police.
Four girls and three boys aged between 5 and 13 were found unconscious and immediately transferred to Dibba hospital.
The children were listed by the Ministry of Education in an Instagram post offering its condolences as: Shoag Saeed Rabeea who was in year two at Al Raheeb School; Khalifa Saeed Rabeea was in year seven at Anas Bin Al Nadar School; Ahmed Saeed Rabeea was in year five at Dhadna School;
Ali Saeed Rabeea was in year three at Dhadna School; Sheikha Saeed Rabeea was in year four at Al Marifa school; Sara Saeed Rabeea and Summaya Saeed Rabeea both attended Al Dana Kindergarten.
"The fire started in the living room and the children died of suffocation from the smoke," Maj Dr Al Hassani said.
Police are still investigating the cause of the blaze.
A funeral for the children was held after Al Dhuhr prayer on Monday and they were be buried at Roll Dhadna cemetery.
On Sunday, Civil Defence said they would begin installing a fire alarm system connecting to the control room in residential buildings and villas this year.
The system feeds back information such as layout, number of occupants, images of the area and access points to Civil Defence before rescue teams reach the area.
On Monday Sheikh Mohammed bin Rashid said the government should cover the cost of installation for those who cannot afford it.
"The Civil Defence of the State has said it is it urgent that fire protection systems connected with the Civil Defence control room are installed in all citizens' homes.
"Security and safety are a priority for us and for all who work in our government," Sheikh Mohammed said.
Sheikh Saif bin Zayed, Deputy Prime Minister and Minister of Interior, responded to the Vice President's request saying his directives will be implemented as quickly as possible, "to enhance and accelerate civil defence projects that seek to protect people and property."