Four people have been killed and dozens wounded in multiple bomb blasts across Thailand.

An explosion occurred in the seaside resort of Hua Hin early Friday morning, less than 12 hours after separate twin bomb attacks killed one person and injured 20, including foreigners.

Two explosions also struck the southern province of Surat Thani, another hit the southern province Trang and yet another two bombs blew up in the tourist area of Phuket.

"The bombings have the same attack profile," Army General Danai Kritmethavee told reporters. "We believe at this time that this was a coordinated attack."

Junta chief Prayut Chan-O-Cha said he would not speculate on the motive behind the attacks, but suggested the bombings were an attempt to stir up chaos.

"The bombs are an attempt to create chaos and confusion," he said.

The bombings come a week after a referendum put forward by the military junta was approved, paving the way for a new constitution and elections next year. Opponents of the military-drafted constitution argue it is laced with undemocratic principles and was designed to keep the military in power for five more years.

Thailand is faced with a low-level insurgency in three majority-Muslim southern provinces, but attacks are usually localized to the region.

The coordinated blasts on Thursday and Friday come several days before the one-year anniversary of the last major attack on tourists in Thailand. A bomb in the Thai capital ripped through a Hindi shrine and killed 20 people on August 17, mostly foreigners.

Thai authorities accused two Uighur men from western China of the bombing, the deadliest attack of its kind in Thailand in recent years. The two accused have denied involvement in the attack and their trial is set to begin later this month.

cw/kl (AFP, AP, dpa)