Seoul ready for Nuclear Security Summit

South Korea has tightened security as world leaders arrive in Seoul for this year's nuclear security summit.
The leaders of 53 countries and representatives of 4 international organizations will open the 2-day conference on Monday.They will discuss measures to prevent terrorists launching nuclear attacks.

Thai Prime Minister Yingluck Shinawatra, Turkish Prime Minister Tayyip Erdogan and other world leaders were welcomed by South Korean officials at the airport outside Seoul on Saturday.

The host country's president, Lee Myung-bak, is expected to hold bilateral meetings with 25 leaders, including US President Barack Obama and Chinese President Hu Jintao.

South Korean military and police are deploying more than 50,000 personnel amid fears of provocations by North Korea during the summit.