A dozen of people were also injured and several shop houses burnt to the ground in new violent attack on civilian targets by Muslim militants during the Ramadan fast period.
Security authorities in the deep South reported the bomb attacks in two southern provinces happened almost at the same time.
One attack in the Thai side of Padang Besar border market town at 8.20 pm Friday involved a motorcycle bomb.
They said the Honda Wave motorcycle was parked in front of “Krok Tong” karaoke bar since the afternoon. It was detonated at night when the bar opened.
Two female employees of the bar were killed and four others injured.
The dead victims were identified as Ms Nujarin Nunchiangkrue, 28. She died at the scene.
Mrs Aron Tammakjan, 42, a resident from Nong Khai, died at Oafang Besar hospital.
Four other female employees were admitted to Hat Yai hospital and Prince of Songkhla University hospital in Hat Yai
Security officials said investigation revealed later this morning that the motorcycle was stolen from Mae Larn district of Pattani last year.
Explosive Ordnance Disposal (EOD) and forensic police were inspecting the scene to collect evidence this morning.
Meanwhile six bomb explosions were reported in Su-ngai Kolok border of Narathiwat last night and shortly after midnight.
Police said two explosions were caused by hand grenades and the others were home made bombs detonated by mobile phone signals.
They said five employees of a karaoke bar were injured by shrapnels of a third bomb explosion after two hand grenades were lobbed into two adjacent restaurants by an assailant suspected to be militant.
According to eyewitnesses, the pillion rider of a motorcycle lobbed a hand grenade at Jenny restaurant on Looksua Anusorn 4 road in Tambon Su-ngai Kolok at about 6.15 pm on Friday. The explosion damaged several chairs but did not cause any injuries because the restaurant was almost empty at the time.
Shortly afterward, another grenade was lobbed in Pat Korean beef restaurant on Looksua Anusorn 5 road believed by the same assailant. The blast caused some damages to the roof.
As security forces were inspecting the scene of the second grenade attack, a bomb exploded in the bushes beside Prachaphiwat Soi 2 road. The explosion broke some glass windows of “Busaba” karoke and injured five female employees who were inside the shop at the time.
Police said that the same group of assailants might have planted the bomb in the bushes before two of them attacked the karaoke bars.
Two latest bomb attacks happened shortly after midnight Saturday in Su-ngai Kolok, killing three and injured a dozen.
The first explosion happened in front of Caltex pump station on Soi Darling off Wongwithi road, and the second at “Somchai” auto spare parts shop behind Genting hotel market.
The two bomb explosions near the station and at the spare part shop triggered two huge fires.
One at the spare part shop raged fiercely because of the paint and thinner gallons it stored inside.
Three persons were trapped inside a room where its windows were fixed with anti theft metal grills.
Several fire engines were rushed to combat the two fires but couldn’t rescue the three trapped inside.
The fires died down before dawn Saturday.
EOD and forensic police were at the two scenes to find evidence to hunt down the Muslim militants.
Following the violent attacks in both provinces security throughout all southern towns were placed at maximum precaution with all roads leading into economic towns in the south deployed by troops and police checking all vehicles.