GENEVA - The international community started to send disaster relief teams on Saturday to help Japan after it suffered a massive earthquake and tsunami, with the United Nations sending a group to help co-ordinate work.

A Korean rescue team transports baggage to prepare departing Gimpo Airport in Seoul March 12, 2011. [Photo/Agencies]

"We are in the process of deploying 9 experts who are among the most experienced we have for dealing with catastrophes. They will help evaluate needs and coordinate assistance with Japanese authorities," Elisabeth Byears, spokeswoman of the UN Office for the Coordination of Humanitarian Affairs (OCHA), told Reuters.

The team of UN disaster relief officials includes several Japanese speakers and an environmental expert, she said.

An explosion blew the roof off an unstable nuclear reactor north of Tokyo on Saturday, raising fears of a disastrous meltdown.

Japanese Chief Cabinet Secretary Yukio Edano said there had been a radiation leak at Tokyo Electric Power Co's (TEPCO) Fukushima Daiichi nuclear power plant.

The 8.9-magnitude earthquake -- the strongest recorded in Japan -- sent a 10-metre (33-foot) high tsunami ripping through towns and cities across the northeast coast on Friday. Japanese media estimate that at least 1,300 people were killed.

The UN announced late on Friday that four foreign search and rescue teams (Australia, New Zealand, South Korea and the United States) were on their way after Japan requested help.

Singapore is also deploying an urban search and rescue team in Japan, Byears told Reuters on Saturday as Switzerland announced it was sending a team of some 25 rescue and medical experts accompanied by nine sniffer dogs. Britain also said it was sending help, after receiving a request form Japan.

The Swiss team will be charged with searching for victims underneath the debris of the tsunami, Toni Frisch, head of the Swiss Humanitarian Aid Unit said on Swiss radio.

The Swiss unit is a militia corps with a pool of at least 700 people ready for duty whose skills range from engineering, seismology, telecommunications and war surgery.

Korean rescue team members handling search dogs prepare to depart Gimpo Airport in Seoul March 12, 2011. [Photo/Agencies]