Thailand on Friday mourned victims of a mass shooting at a childcare center in northeastern Nong Bua Lamphu province, which has led to at least 37 deaths, most of them children.

On Friday morning, grief-stricken families laid white flowers on the steps of the center, the scene of the shooting rampage by a sacked police officer.

Thai Prime Minister Prayut Chan-o-cha visited the childcare center Friday, and Thailand's King Maha Vajiralongkorn and Queen Suthida were expected to go to hospitals later in the day, where seven of the 10 injured people remain.

"The government and I are very sorry, and so are the people of Thailand," Prayut told relatives of the victims after laying flowers at the center.

Students, teachers and government officials in some provinces also mourned the victims of Thursday's incident, while flags of government organizations across the country were flying at half-mast.

Police identified the attacker as Panya Kamrap, 34, a former police officer who was dismissed from his post in June over drug allegations. He was supposed to face trial on drugs charge in court on Friday, national police chief Damrongsak Kittipraphat told a press conference Thursday.

In response to questions about the attacker's mental state when he intruded into the center, Damrongsak said on Friday that the autopsy result of the attacker has showed no illicit drug usage during the past 72 hours.

"We are double-checking the result as the attacker has been involved in drug abuse before," Damrongsak told reporters.

On Friday, government spokesperson lowered the death toll number to 37, from the count of 38 released by police Thursday, with both numbers including the attacker and his family members, who were found dead at his home.

Acting government spokesperson Anucha Burapachaisri said that government agencies have provided assistance to the wounded and families of the deceased, totaling 13.19 million baht (about 352,000 U.S. dollars).

Seven of the 10 injured people remained hospitalized, including six critically injured, the Nong Bua Lamphu provincial hospital said on the social media platform of Facebook.

All the injured people have showed a good sign of recovery, Deputy Prime Minister and Minister of Public Health Anutin Charnvirakul told reporters.

After the incident, the government has vowed to strengthen anti-drugs efforts and gun ownership regulation.

At an emergency meeting held Friday, Suthipong Chulacharoen, permanent secretary of the Ministry of Interior, urged intensified efforts to implement the country's anti-drugs policies and better review the qualifications for possessing and using firearms.