Four army officers will be questioned and charged over last month's alleged assassination attempt on Thai Prime Minister Thaksin Shinawatra, a senior police officer said Monday. Lieutenant General Montri Jamroon said police had asked the defence ministry to send the four to them for questioning. "They will be questioned and will be charged with attempted premeditated murder and illegal possession of explosives," he told AFP.Police on August 24 defused a potent mix of TNT, plastic explosives, fertiliser and fuel oil left in the trunk of a car by an intersection near Thaksin's house in what they said was an attempt to kill the prime minister. An army officer was arrested shortly after the bomb was found and charged with illegal possession of explosives. Thaksin later said a group of up to four military officers had schemed to kill him. Montri said police had information linking the four officers waiting to be questioned with the suspect already in custody, who is also due to be charged with attempted premeditated murder. One of the four officers will be questioned late Monday, Montri said, while the others will see police Thursday.