The first bomb went off at about 6am in Narathiwat's Tak Bai district, injuring a grandmother and grandson as they prepared food for sale at a roadside shop.

Neay Kongsamret, 68, was in serious condition, while Pornchai Kongsamret, 14, was slightly injured.

Police said militants might have hidden the bomb overnight as an eyewitness had seen a few men near the site the previous evening during a heavy rainstorm.

Another bomb exploded at around 1pm at a cockpit, also in Tak Bai district, injuring three people, including two women who were selling food.

In neighbouring Yala province's Raman district a roadside bomb went off but missed the target as a group of soldiers on patrol had already passed by.

In Pattani's Yarang district two gunmen on motorcycles shot a husband and wife, Chaiyan Siriwat, 43, and his wife, Sunan Suwan, 43, on the Pattani-Yala Road.

Killings have taken place on a daily basis since the beginning of 2004, and more than 2,000 people have been murdered so far as the government struggles to contain the violence.

Intelligence agencies issued a warning of a possible major incident today as militants might create trouble to commemorate the bloody uprising on April 28, 2004 when 32 militants were killed at the historic mosque of Krue Se.

In Bangkok Army chief Sonthi Boonyaratglin said there would be no major incident today as the uprising was "not important" for the insurgency movement. Many militants "used only knives" to fight with well-equipped soldiers.