Deputy Prime Minister Prawit Wongsuwon denied the Chinese government has issued a warning to its citizens against visiting Thailand following an airport security guard's alleged assault on a Chinese tourist.

The government has already apologised to Beijing, which was satisfied with Thai authorities' handling of the matter, Gen Prawit said Wednesday.

The security guard involved in the incident with the tourist at Don Mueang airport has been fired, the deputy prime minister said, adding the incident was a "personal matter".

The altercation, videoed by another Chinese tourist, occurred inside the airport last Thursday. The clip was posted on Facebook and drew fierce criticism of the guard.

The clip showed the guard and the Chinese man quarrelling before the guard shoved him and swung his arm wildly, as if trying to punch the tourist in the face. He missed and another security guard intervened.

The 109-second video was widely shared and caused a panicky reaction from the government.

The Chinese tourist had been denied entry because he did not have proof of a ticket home.

Gen Prawit said Chinese tourists to Thailand were well cared for and everything had gone smoothly before the deadly boat accident in Phuket in July and the Don Mueang airport incident.

The government has been trying to contain the damage to the tourism sector caused by the capsize of the dive boat Phoenix, which sank during a storm off the Phuket coast on July 5, drowning 47 Chinese tourists.

Also Wednesday, Prime Minister Prayut Chan-o-cha stressed the need to boost safety for tourists to restore their confidence. He admitted a string of negative incidents had hurt the country's tourism sector.

"We have to be patient and try to restore the country's good image," Gen Prayut said during an inspection trip to Lamphun in the North of the country.

Pol Maj Gen Surachate Hakparn, the newly appointed Immigration Bureau commissioner, said he had met officials from five airports -- Don Mueang, Suvarnabhumi, Phuket, Krabi, and Samui -- to discuss measures to prevent Chinese tourists suffering bad experiences.

Pol Maj Gen Surachate also talked about reports of bribes during the process of issuing visas on arrival to Chinese tourists, admitting some had been asked to pay "tips" to speed up the process of filling out immigration forms.

He said Chinese and Thai tour operators asked tourists for tips and gave them to immigration officers to help things go more smoothly.

"But from now on, I have ordered immigration officers not to receive tips, and asked airport directors to hold meetings with tour operators to tell them not to ask for 'tips' from tourists," Pol Maj Gen Surachate said.

"No Tips" stickers written in English and Chinese were pasted onto visa-on-arrival counters at all international airports in Thailand to assure tourists they will not have to pay tips.