North Korea has fired two short-range missiles into the sea off the east coast of the Korean peninsula, South Korea's defence ministry has said, after launching similar rockets last week.

South Korea's Yonhap news agency said the missiles likely flew about 500km after being launched on Monday, adding that they were believed to be Scud-C models.

South Korea's defence ministry has said the Scuds are normally fired using mobile launch pads which can be activated with minimal preparation.

"North Korea fired two missiles, which are suspected as short-range ballistic missiles, at 6:19 this morning from Wonsan area towards open sea in a northeasterly direction." South Korea's Defence Ministry spokesman Kim Min-seok said at a regular news briefing.

"North Korea is taking peace offensive and provocative acts at the same time. We strictly warn against such acts and strongly urge to stop them immediately."

The distance would mean the weapon can hit targets in South Korea and Japan.

Launches by the North of short-range missiles are not uncommon as part of regular military exercises.

The firing came days after the beginning of annual US and South Korean joint military exercises, which the North routinely denounces as a preparation for war.

Source: Agencies