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.

Why is North Korea testing missiles?

A statement released by North Korea's Foreign Ministry on Tuesday does not mention the missile launches but it claims that the military drills in the South essentially force it to develop and test new weapons. Given the drills in the South, "we are compelled to develop, test and deploy the powerful physical means essential for national defence," the statement said. It also described the exercise as "an undisguised denial and a flagrant violation" of the recent talks between the US and North Korea (DPRK). "We have already warned several times that the joint military exercises would block progress in the DPRK-US relations and the inter-Korean relations and bring us into reconsideration of our earlier major steps," the statement warns.BBC