South Korea has raised its surveillance alert level amid indications that North Korea is preparing for a missile test.

At least one previously untested missile with a 3,000km (2,000-
mile) range is fuelled and ready for launch, US and South Korean
sources say.
Pyongyang has been making bellicose threats against South
Korea, Japan and US bases in the region.
The threats follow tough new UN sanctions imposed on North
Korea last month following its third nuclear test.
Separately, an initial investigation by the South into a major
cyber attack last month that affected a number of banks and
broadcasters has said the North is to blame.
'Anytime now'
North Korea is believed to have completed preparations for a
missile launch after it moved two Musudan missiles to its east
coast, Yonhap news agency says.
In anticipation, the South Korea-US Combined Forces have raised
their alert level to Watchcon 2, to increase surveillance
monitoring, Yonhap quoted a senior military official as saying.
North Korea unveiled the Musudan missile during a military
parade in 2010 but has yet to test it. There are reports, however,
that it may have been sold to Iran and tested there.
The launch could happen "anytime from now", South Korean
Foreign Minister Yun Byung-se told parliament.
North Korea has tested intermediate range missiles before and
during periods of crisis and tension, says the BBC's John
Sudworth in Seoul.
So while another test launch would certainly be seen as
provocative and a breach of UN Security Council resolutions, it is
unlikely to have any major, short-term military significance unless
it goes wrong, our correspondent adds.
The raising of South Korea's alert status comes as Japan
deployed anti-missile defences in Tokyo as a precaution.
"We are on high alert," said Japan's Defence Minister Itsunori
Onodera.
Meanwhile, an official investigation by the South into last
month's cyber attack traced the malicious codes used to six
computers in the North.
"We've collected a lot of evidence to determine the North's
Reconnaissance General Bureau led the attack, which had been
prepared for at least eight months," a spokesman for the Korea
Internet and Security Agency said.
The attack on 20 March severely affected the KBS, MBC and YTN
broadcasters and operations at the Shinhan, NongHyup and Jeju
banks.
'Uncontrollable'
The North has warned foreigners in South Korea to take
precautions in case of war.
On Tuesday, UN Secretary-General Ban Ki-moon warned the crisis
on the Korean peninsula may become "uncontrollable".
He once again urged North Korea to tone down its "provocative
rhetoric" and to keep open a joint North-South Korean industrial
complex.
North Koreans failed to report for work at the Kaesong complex
on Tuesday, suspending one of the few points of co-operation
with South Korea.
Since the UN sanctions were imposed, Pyongyang has threatened
to use nuclear weapons and has said it will restart a nuclear
reactor.
The North has also shut an emergency military hotline between
Seoul and Pyongyang.
Last week, it warned it would not be able to guarantee the safety
of foreign embassy staff after 10 April, and that countries should
begin evacuating their diplomatic staff.