Copies of the watches were distributed to the vendors during a meeting with the police in July, a Songkhla vendor said.

"At the meeting police said that only genuine digital Casio watches could be used in making bombs. The fake ones cannot be used," the vendor said.

Songkhla police chief MajGeneral Worapong Shewpreecha revealed at the weekend that suspected militants in the three restive southernmost provinces - Pattani, Narathiwat and Yala - had been coming to Songkhla's KimyongSantisuk Market to buy mobile phones and watches, both of which are important components in making bombs.

The suspected militants bought large amounts of mobile phones and watches of the same brand, prompting suspicious vendors to report the purchase to the police.

Meanwhile two men who were buying Durians were killed, and a third injured Monday by suspected Islamic insurgents in Yala province, police said.

At least four suspects on motorcycles killed the two men and seriously injured the third in a drive-by shooting in Yala. The three stopped to buy Durians at a roadside.

However police did not rule out possibility that personal conflict could be a cause of the attack.