Groups of armed men attacked a police station and a government office Monday in southern Thailand (search), less than 24 hours after the area was shaken by bombings that killed two people at its main airport.

The organized assaults in Joh Irong district of Narathiwat province (search), and Sunday's deadly bombings in nearby Songkhla province (search), raised concerns an Islamic insurgency in the region was gaining momentum.

No casualties were reported among the defenders in Monday's assaults, in which the attackers used one or more M-79 grenade launchers, said police Col. Thanongsak Wangsupah.

He said the attackers operated in two groups of about 10 men each, fleeing to the forest on a nearby mountain.

As night fell, security forces were pursuing the attackers, he said.

"If they keep fighting, we probably can't catch them alive," said Narathiwat Governor Pracha Tharath, who indicated authorities had been warned about the attacks.

Earlier Monday, a bomb buried in a road in neighboring Yala province (search) wounded four soldiers.

The attacks came despite security forces being put on high alert after two people were killed Sunday night by a bomb at Hat Yai International Airport (search) in another southern province, Songkhla.

A department store and a hotel in the province were also bombed, and more than 70 people in all were wounded.

The bombings set off fears that Muslim insurgents who had previously restricted their attacks to the southernmost provinces of Yala, Narathiwat and Pattani were broadening their theater of operations.

Since January 2004, almost 800 people have been killed in sectarian violence in the provinces. The Muslim militant suspects have generally restricted their almost daily attacks to hit and run shootings carried out by one or two gunmen and small bombings.

Songkhla is just north of the three Muslim-dominated provinces, and Hat Yai is the biggest city in Thailand's far south.

Airports, railway stations and other tourist destinations throughout the south were on full alert after the Songkhla bombings.

Interior Minister Chitchai Wannasathit said authorities have pictures of the attackers at the airport from closed-circuit cameras, but declined to give further details.

The airport bomb was left in a bag by a man in the waiting area, Gen. Chaiyasit Shinawatra, the Thai military supreme commander, said earlier.

Prime Minister Thaksin Shinawatra (search) condemned the blasts, expressed his condolences to the victims and said security had to be strengthened.

Thaksin has been criticized previously for adopting an iron-fist policy that critics said would only breed more insurgents. However, he has recently called for a more measured approach that would de-emphasize military action.

Southern Thailand's Muslim minority has long complained of discrimination by the central government. Thailand is predominantly Buddhist.