Chief Electoral Officer P K Jajoria said barring reports of a couple of sporadic incidents, voting was "progressing peacefully with an impressive turnout of voters".
A landmine was detected at Hariharganj under Hussainabad Assembly constituency in Palamau district and was defused, he said. A couple of "fake explosives" were also recovered and there was no cause for worry, he said. Para-military forces were manning the areas, he said.
26.5 percent polling was reported till 11 AM and Jajoria said he expected better polling percentage this time than the previous elections.
Voting was picking up in the rural areas, he said. Braving the chill, women in large numbers had lined up in front of the polling booths even before polling began at 7 AM. Voting will end at 3 PM.
All the 13 seats are spread over the six Maoist affected districts of Palamu, Gumla, Lohardaga, Chatra, Garhwa and Latehar.
Ten sitting MLAs, including one minister, and several former ministers are among 199 candidates trying their luck today.
The Assembly seats going to polls include Chatra (SC), Gumla (ST), Bishunpur (ST), Lohardaga (ST), Manika (ST), Latehar (SC), Panki and Daltonganj, Bishrampur, Chhatarpur (SC), Hussainabad, Garhwa and Bhawanathpur.
A total of of 33,61,938, including 15,77,090 women voters, are eligible to exercise their franchise in the first phase to choose among the candidates, including 18 women and 72 independents.
This is the third Assembly election in Jharkhand which was carved out of Bihar in 2000.