Grocery store owner Prempreeda Chumnum was attacked while descending from the pedestrian bridge at Soi Ramkhamhaeng 142 and her purse containing Bt87,000, which she was on her way to deposit in a nearby bank, was snatched.

The 23-year-old woman sustained minor injuries to the head, but her two-month-old pregnancy was unaffected.

Yannakorn Ekkarat, a taxi motorcyclist, witnessed the robbery and chased the two men as they ran towards a waiting pickup.

He gave up the chase and threw a stick at the vehicle, whereupon one of the robbers lying in the bed of the pickup shot him in the arm. The truck then sped away.

Yannakorn suffered only minor injury in the incident.

Quoting a witness, Bang Chan police said the pickup was an Isuzu D-Max model painted a pink-purple shade with the registration number Por Or 815, though the province of registration was not clearly seen.

Pol Maj-General Witthaya, chief of Metropolitan Police Region 4 which includes the robbery scene, said he believed the culprits were a three-man gang that had robbed a petrol station on Krungthep Kreetha Road and committed muggings in the Bang Chan area.