Samut Prakan Province

The Japanese Hakabusan Maru, posing as a merchant ship, entered the Gulf of Thailand on December 7, 1941 , and anchored off at a position approximately six kilometres west of the lighthouse at San Don. Aboard was Lieutenant Colonel Yoshida's "Bangkok Holding Unit", comprising the 3rd Battalion of the 4th Imperial Guards Regiment along with a battery each of antitank and field guns.

At 03:30 on December 8, Lieutenant Commander Luang Wuthwariron set off in a patrol boat to inspect the Hakabusan Maru. Upon seeing khaki-clad soldiers onboard the ship, he turned around and headed for the mouth of the Chao Phraya River to raise the alarm.

Meanwhile, at the Bang Pu Recreational Park, Warin Amatayakuln, the manager, was woken up from his slumber by the noise of motorcars, apparently moving up Sukhumvit Road from behind his bungalow. An hour later, he was informed by an employee of the park that enemy soldiers have landed and detained the staff in their quarters (located at the Sukhta Pier).

Warin subsequently attempted to call the police, only to find the telephone lines dead. A bus driver by the name of Chamlong was instead despatched to the police station in Samut Prakan town.

It was not until 05:00 that Police Major Phuen Thongthiw received news of the invasion at Bang Pu. While he telephoned Bangkok , his deputy, Police Captain Jinda Komlasut, ordered Police 2nd Lieutenants Khien Kuncharanusorn and Suwit Iksiln to take a detachment of 20 men to confront the invaders.

Travelling in Chamlong's bus, the rifle-armed policemen suddenly came upon two Japanese-commandeered trucks speeding towards them at a bend in the road near Kilometre Sign 9. Suwit promptly had the bus parked in the middle of the road, with his men deployed alongside it. The two trucks were thus forced to come to a halt some distance away from this ad hoc roadblock. There appeared a soldier waving a white-coloured cloth, stitched on which was a picture of two hands locked in a handshake.

Police 2nd Lieutenant Suwit then proceeded to walk forward and greet the solitary figure in English. Claiming to be the Japanese Embassy's deputy military attaché, the man quickly explained to the Thai that an agreement had been reached by their respective governments and that Japanese troops have been permitted to enter Bangkok . Lieutenant Colonel Yoshida at this point turned up to reiterate the attaché's explanation. Suwit's reply was that he had orders to stand his ground and could not do otherwise without explicit orders from his superiors.

Meanwhile in Samut Prakan town, a conference of the local gentry and officials was underway when the mayor, Suwann Ruenyosd came stomping into the room bearing news of the hostile encroachment. The meeting's topic immediately changed from that of the upcoming Constitution Day's festivals to how to deal with the invaders.

The Mayor enthusiastically called for the townsfolk to take up arms and set up a position by the Samrong Canal , where they would "engage" the enemy until a relief force arrives. Two men, Niti Ratthanonth and Wichien Rochanutama, swiftly left to recruit volunteers and to mobilise the local Yuwachon Thaharn company.

Further up the river was the Naval Academy , where the senior officer, Commander Luang Praditthanavawuth, had his cadets woken up to form a defensive line alongside the Mahawongsa Canal.

Also preparing for an engagement that would never come was Lieutenant Commander Khloi Mahasukhonth, commander of the Phra Chulachomklao Fort, who had called for his men to take up battle positions, ready to halt any enemy crafts attempting to force their way up the Paknam river mouth.

It was a little after 08:00 that Police Captain Jinda finally appeared at Kilometre Sign 9, escorting a delegation sent to negotiate with the invaders. It was headed by Colonel Luang Yodawuth, and included Captain Luang Pradiyathanavayuth of the navy, Police Captain Prasath Sawannasoburn, and the Japanese military attaché, Lieutenant Colonel Yahara. Tagging along were Police Major Phuen and Khun Buriphiramikijd, the province's governor.

The ensuing negotiations lasted little more than forty-five minutes, with the Japanese agreeing to move up as far as the Bang Pu crossroads behind the governor's residence. The Thai policemen were ordered to return to their station, with the exception of Police 2nd Lieutenant Suwit, who was charged with the task of guiding the Japanese to their agreed position.