A crazed gunman is in a 24-hour standoff with police today after firing shots from his home in Thailand.

Police Lieutenant Colonel Kitikarn Sangbun, 51, a member of the Royal Thai Police (RTP) Special Branch, sparked panic in the residential area in Bangkok's Sai Mai district when he fired a barrage of bullets at around 11 AM on March 14.

His colleagues had attempted to take him to a hospital after missing work for several days. When the crew arrived with an ambulance, Kitikarn reportedly shot at them through his door, sending them fleeing.

More than 100 officers later converged on Kitikarn's house and cordoned off the area while evacuating residents.

They tried to negotiate with the cop and also brought his parents to reason with him. However, he still refused to negotiate with them and carried on barricading himself inside.

Deputy national police chief Police General Torsak Sukwimol arrived at the scene at around 6 PM, ordering the officers to avoid using excessive force as Kitikarn had not taken anyone hostage.

They launched several canisters of tear gas into the house but still failed to force him out.

Police chief Torsak said: 'The gunman knows how to avoid tear gas through his training, so the tactic might not work.'

Smatterings of gunshots were heard throughout the ongoing standoff, with one of the bullets hitting but not piercing an officer's helmet.

No one has been reported injured so far.

Kitikarn had still not surrendered by midday local time on March 15. Police are using a thermal drone to monitor him.

Kitikarn was said to have been transferred to the RTP Special Branch's Intelligence Development Centre on January 31.

Sai Mai police superintendent Rangsan Sornsing said: 'Before this incident, Police Lieutenant Kitikarn had been absent from work for a few days due to a mental health condition. His co-workers tried to get him help, but he started firing at them.'