Police seized several homemade bombs and detained nine persons including a student during a four-hour raid in Sungai Petani, Malaysia on Friday.

Around 10 powerful explosives were discovered with equipments such as screws and bolts from two different locations, one in a small workshop and another at a house.

"Initial investigs showed that the bombs, each weighing about 0.5kg, are capable of sending a car three storeys high if detonated under a vehicle," said Kedah police chief Senior Deputy Comm Datuk Ahmad Ibrahim at a press conference on Friday.

Authorities nabbed a gang of criminals and a teenage boy along with another person, who was supposedly working part-time in the crude bomb-making workshop.

"The 14-year-old suspect could be a dropout and we are investigating the motive for his involvement in the group," police said in a statement.

They also stated that investigations are on to ascertain whether the detained group was involved in prior cases of bomb blasts including the recent blast incident in Taman Angsana Sari.

In August, a 32-year-old primary school clerk was killed after a parcel bomb exploded in his hands. Police arrested two suspects in connection with the incident.