AGARTALA/NEW DELHI, Sep 15 (TIWN/IANS): A frontline Sukhoi SU-30 combat jet landed at the civil airport in Agartala on Thursday and departed soon after, with the authorities describing it as a "routine" mission.

Informed sources, however, said this was part of efforts by the Indian Air Force (IAF) to operationalise more air bases in the Northeast region to act as a counter to China.

"A Sukhoi SU-30 MKI fighter aircraft landed at the Agartala airport this morning. It departed soon afterwards," Agartala Airport Director S.D. Barman told reporters.

"This is a part of routine peace-time training activity, nothing else," Defence Ministry spokesman Group Captain Amit Mahajan told IANS on the phone from Shillong.

The IAF had, in August 2010, deployed its first SU-30 squadron in the northeast at Tezpur in Assam. In March 2011, it raised another Sukhoi squadron at the Chabua airbase, also in Assam.

On August 19, three SU-30s had touched down at the upgraded Pasighat Advanced Landing Ground (ALG) in Arunachal Pradesh.

Barman said that there are eight airports in the region, besides a few ALGs in Arunachal Pradesh where the SU-30s can land.