The Air Force detected and expelled a foreign jet fighter that had crossed into the country's airspace above Riau Islands province, on Monday.
"We despatched two Sukhoi aircraft from Hang Nadim airport to intercept the trespassing jet and escort it out of our territory," Tanjung Pinang Air Force Base commander, Lt.. Col. I Ketut Wahyu Wijaya said on Monday.
He added that the Air Force had deployed four units of Sukhoi SU-27 and SU-30 at Hang Nadim airport in Batam, to patrol the nation's airspace.
Wahyu pointed out that an additional Sukhoi could be deployed if needed, depending on the situation.
"We are in a peaceful situation, so the reinforcement of Sukhois at the airport is only a precaution and to safeguard our territory," Wahyu said.
The Air Force is still awaiting detailed data about the trespassing jet.
"We're still waiting for information from the pursuing Sukhoi about the jet's details," he said.
Aircraft from neighbouring countries have frequently illegally entered the country's airspace, raising the government's concerns over border security.