The activities were brought forward as a result of security concerns. Children's Day falls on the second Saturday of January every year, which is January 13 this year.

However, the New Year bombings in Bangkok have generated concern and organisers have particular worries about Children's Day.

"Out of concern for safety we have decided to hold the activities in advance," foundation secretary-general Prateep Ungsongtham Hata said yesterday.

The day encourages children to be well behaved and perform good deeds in honour of His Majesty the King.

In a related development, Education Minister Wijit Srisa-an said the ministry worked closely with the armed forces, police and security officials to ensure safety at events.

"Security will be tightened. We believe the activities will go more smoothly than in any other year," he said.

Science and Technology Minister Yongyuth Yuthavong said the ministry and agencies like the Government Pharmaceutical Organisation would turn Yothee and Rama VI roads into a "science street" from Tuesday to Saturday.

"We have ensured security at the event," Yongyuth said. "We will install a closed-circuit television system."

The minister added that transparent refuse bins would also be used. On New Year's Eve, unknown bombers hid bombs in refuse bins at spots about the capital. They exploded killing three and injuring more than 40 others.

Future Park Rangsit shopping centre yesterday denied rumours that a bomb had exploded there, injuring many.

"The rumours are untrue," centre sales and business-development director Jittinan Wanglee said.

She said it would hold Children's Day activities between January 13 and January 21. About 600 security officers will be on hand.

"On normal days we have about 200 officers," she said.

Jittinan added that shopper numbers had dropped by 10-15 per cent following the bombings.

Meanwhile, Bangkok Governor Apirak Kosayodhin yesterday visited the busy Chatuchak weekend market, which attracts between 200,000 and 300,000 visitors a day.

More than 100 uniformed and plain-clothes police, military and security officials were on duty. Security warnings were broadcast in both English and Thai.

Apirak said refuse bins were being inspected and the use of clear bins was being encouraged.

Bomb hoaxes continue. At Suvarnabhumi Airport an Airports of Thailand official was detained after joking about carrying bombs.

"I joked with an official I knew. Others might have overheard and believed I was carrying bombs," the man said on condition of anonymity.

Metropolitan Police tracked down a nine-year-old who used his mobile telephone to report a bomb to the 191 emergency hotline.

On Friday, the boy told the hotline a bomb had been planted at Victory Monument. Police rushed to the monument but found nothing. They are considering charges.

Samut Sakhon police were called to a bank in Muang district to inspect a suspicious black plastic bag, which turned out to be harmless.

Muang Samut Sakhon police superintendent Colonel Chumpol Chantajamras-silp said information from the public was welcomed.

He asked people not to leave unattended bags or other items in public places.