Two Myanmar air force bases came under rocket attack on Thursday, the military said, as the country grapples with violence in the wake of the February 1 coup.

Myanmar has been in turmoil since the generals seized power, ousting civilian leader Aung San Suu Kyi and unleashing a wave of near-daily street protests calling for a return to democracy.

Security forces have sought to quell the unrest with a brutal crackdown on protests, with more than 750 civilians killed, according to a local monitoring group.

Fighting has also flared up between the military and Myanmar's numerous ethnic rebel armies, some of which have backed the protest movement and sheltered activists on the run from the junta.

A military spokesman said air bases in the central cities of Magway and Meiktila came under rocket fire early on Thursday morning, but no damage was done.

It is not clear who was behind the attacks, but the military has launched air strikes in recent weeks against the Karen National Union (KNU), one of the leading ethnic rebel armies.

The KNU, which holds territory along the border with Thailand, on Tuesday attacked and razed an army post, prompting the military to respond with air strikes.

The surge in clashes between the military and ethnic rebels has prompted some observers, including the UN, to warn that the country's crisis could spiral into a broader conflict.

© AFP