The suspected students also killed his grandparents before going to school. They were found dead at home, authorities say.

The 9mm handgun he used belongs to his grandfather, who was a teacher, police say.

Police had earlier said that six people were killed in school shooting, but authorities have now clarified that four others have been killed so far in the school, all of whom were teachers. The suspected gunman has also been found dead.

An opposition leader has called for Thai authorities to review the country's gun control measures.

"Although the motive behind the attack remains unclear at this time, an act of violence in an educational institution, which should be one of the safest places in our society, serves as a stark reminder for Thai society to seriously and systematically review gun control measures," Natthaphong Ruengpanyawut, leader of the People's Party wrote in a Facebook post following the shooting.

Natthaphong also expressed his condolences to the families of the victims.

Jonathan Head
BBC South East Asia Correspondent

Shots were reported from the Nonthaburi branch of the Debsirin School on the outskirts of the capital Bangkok, just after 10:00 local time (03:00 GMT)

Videos from the scene show staff rushing students out of the classroom and police officers trying to find the shooter.

According to the police, he was a 14-year-old student at the school who opened fire on teachers and fellow pupils before taking his own life.

The injured were treated by paramedics before being taken to hospital.

This shooting follows another at a school in southern Thailand in February. That incident raised questions, which will now surely be asked again, about the easy availability of guns in Thailand.

The shooting took place on the outskirts of Thailand's capital, Bangkok, in the well-known Debsirin School.

Thanyarat Doksone
Producer, BBC News Bangkok

We just spoke to a seventh-grade student who has fled the building. She says she was in her classroom when she saw the shooter walking from room to room.

He then shot the teacher who was standing in front of her classroom, she says.

She couldn't see anything else after that, she recalls.

Thanyarat Doksone
Reporting from Bangkok

Our team has arrived at the scene, where many other media outlets have also gathered outside the school gate. We see several ambulances parked inside the school’s sports grounds.

At least two schools in the vicinity, including one preschool, have halted classes so students can go home early.

Emotions are running high outside Debsirin Nonthaburi School. Staff and students have been evacuated from the premises after the shooting.

Here are the latest pictures from the scene.

Image source, Reuters

Image source, Getty Images

Image source, Reuters

Image source, Reuters

Six people have died in the shooting, police have told reporters at the scene.

Thai police had earlier said that the suspected shooter is also dead.

At least 15 people are injured - of which two are in a critical condition, police say.

Speaking to reporters earlier, Thai Prime Minister Anutin Charnvirakul expressed condolences for the victims of the school shooting.

"This is really bad, it shouldn't have happened. I don't just feel sorry for the victims but I feel sorry that this happened. How can this happen in our country," he said in a short interview at the government house.

"This is why the government do not allow [citizens] to posses firearms", he added.

Image source, Reuters

One student told Reuters that he had thought the sound of gunshots during the school shooting were firecrackers going off, or someone banging something.

"I didn't think it was a gun at first," he said.

"There were many shots: bang bang bang. Then it went quiet. Then it started again."

Students were seen fleeing from the school shooting site, and staff members from the Debsirin Nonthaburi School looked visibly distraught waiting outside the school.

Gun laws are quite strict in Thailand, where illegal possesion of firearms can lead to a sentence of up to 10 years. But the country still has one of the highest civilian gun ownership rate in South East Asia.

The country has seen several deadly incidents in recent years.

In February, a school principal and a female student were shot by an 18-year-old gunman during a school siege in southern Thailand. The principal died in hospital the following day.

Last year, five people were killed in a shooting at a food market in Bangkok.

The shooter was in the ninth grade, Dechrapee Kongdee, chief of the Nonthaburi provincial police, tells the BBC.

Ninth grade students in Thailand are typically around 14 years old.

We reported earlier that police said the shooter has died.

At least two people have died in the school shooting, according to media reports citing police.

Two people were killed and 15 were injured, according to broadcaster Thai PBS.

Reuters is reporting that a teacher was killed and four other people were injured. The shooter killed himself, Reuters reported the police as saying.

Here are some of the latest photos we're getting from the scene:

Image source, Reuters

Image source, Reuters

Image source, Reuters

The suspected shooter is dead, according to Thai police and local media.

It's unclear if they were shot by the police or if they killed themselves.

We'll bring you the latest updates once we get them.

Image source, Reuters

The Debsirin School is a well-known secondary school that has branches across the country.

Its branch in Nonthaburi, where the shooting is happening, is located in the northwestern outskirts of Bangkok.

The original Debsirin School in Bangkok was founded by Thai King Chulalongkorn in 1885. Many public figures in Thailand have attended the school, including diplomats, athletes and even several prime ministers.

The school and its various branches are widely associated with educational prestige in Thailand.

In their latest update, published on Facebook just minutes ago, the police are warning of a report that the shooter is in the school computer room.

"Who is still stuck there? Hide securely," the police wrote in their statement, urging people to wait for authorities.

Police said there were fatalities at the shooting, Reuters reports, quoting the head of a local police department.

The report said the number of deaths were not yet known.

Police are warning people to stay away from the area amid an ongoing shooting at the Debsirin School in Nonthaburi, a franchise of a well-known school in the region.

"Anyone trapped inside a building, hide, close everything tightly, and wait for rescue personnel to arrive," the police has just posted on its Facebook page.

• Injuries have been reported in a school shooting involving students near Bangkok
• It is taking place in the Bang Kruai district of Nonthaburi province. Police have identified the perpetrator as a student
• The situation is still active as of 10:27 local time (04:27 BST), Police Col Passakorn Chaitaweewong tells the BBC