The Naxals, who usually target security forces with manual improvised explosive devices, are now slowly developing remote-controlled IEDs which can be activated from a distance with just the push of a button.
The improvement in fire-power is being supported by intensive training on the lines of regular forces,say sources.
Central security agencies and local police sources say the Maoists have started two factories each in the dense forests and hills of both Jharkhand and Chhattisgarh.
Sources say that though another such factory existed earlier in Bihar, the Naxals have dismantled it.
Early last year, a combing team of the CRPF and the local police had come across one such unit used for making small bombs and mortar shells in Jharkhand.
The Naxals who are trying to improve their firepower have also come out with the deadly 'Claymore Mines', or what are often called 'directional IEDs'.
Unlike in the past, when IEDs use to be buried beneath the road in a small can, the Claymore Mines, which come with a thick aluminium plate, can be fitted to a tree.
The IED, when exploded, will deflect the shrapnels in a direction opposite to the plate, thus focusing them to a particular area as against conventional IEDs where the impact is in a circular area around the device.
Certain blasts in Chhattisgarh have pointed to the possibility of remote-controlled IEDs being used but they are yet to become a standard strategy for the Naxals, say sources.
"Naxals are constantly trying to improvise and have also set up factories for this. During searches by security personnel, they have come across few chips which suggest that they are trying to develop remote-controlled IEDs. If they succeed, it would prove deadly," according to a source.
"The Naxalites also make their own guns besides those snatched from policemen and procured from outside. Their locally-made guns called 'pahar' can be used to severely injure a person if not kill him. The pellets break into pieces on impact and hence are deadly," the source says.
The left-wing extremists are known for using gelatin sticks in their explosives. They are sourced from mining areas, sources say.
A source says that the Maoists also undergo military training similar to that of securitymen, which "suggests a possibility of ex-army or ex-policemen" helping in preparing training modules, whether due to force or their own wish.
One of the Naxal training CDs seized by security forces in Andhra Pradesh gives an insight into the training modules with the militants practising crawling backwards.
Security forces have also come across abandoned centres of Naxals having rope climbing, ladder, crawling tunnels and other obstacles used for hard training.
The Naxals have also hit upon an innovative way to store their ammunition by hiding it in branded plastic water tanks placed in the ground and covered with mud and stones.
Sources said the logic behind it was that there are less chances of formation of moisture, which might damage the ammunition.