North Korea has fired two unidentified missiles, its fourth such launch in less than two weeks, South Korea's military has said.
They were fired from South Hwanghae province across the peninsula into the sea to the east, a statement said.The North again expressed anger at US-South Korean military drills that began on Monday.
It says they violate agreements reached with US President Donald Trump and South Korea's President Moon Jae-in.
While the main drills will start on 11 August, low-key preparation has begun.
The US said it was monitoring the situation and consulting with South Korea and Japan.
Late on Monday, Washington introduced travel restrictions on people who have visited North Korea. Anyone who would normally be eligible for the US visa waiver programme will now have to apply for a US visa if they have visited North Korea in the last eight years.
The new policy affects tourists from most European countries as well as Australia, New Zealand, and several Asian countries like Japan, Taiwan and Singapore.