VIENNA - The International Atomic Energy Agency (IAEA) said Wednesday that more needs to be done to improve the safety of nuclear and radioactive materials worldwide, citing security incidents which happened in recent years.

Khammar Mrabit, director of the IAEA's Office of Nuclear Security, made the remarks at a press briefing at the UN nuclear watchdog's headquarters in Vienna, ahead of next week's Nuclear Security Summit in Seoul.

"Nuclear and other radioactive materials are still not properly secured. We have roughly around 200 incidents per year," he said, adding that "continuous improvement is a must. Complacency is bad."

According to information from the IAEA's Illicit Trafficking Database (ITDB), from 1993 to 2011, more than 2100 incidents of nuclear and radioactive materials had been confirmed, of which about 400 incidents involved unauthorized possession, movement or attempts to illegally trade or use of nuclear and radioactive materials.

Regarding the protection against potential nuclear terrorist activities, Mrabit said that the IAEA provided technical support to many countries in this regard, through the "International Physical Protection Advisory Service(IPPAS)."

The IPPAS helps strengthen national nuclear security system through evaluation of existing physical protection arrangements, state's systems and arrangements at facilities and locations.

Mrabit also mentioned that over 10,000 people from some 120 countries have been trained by the IAEA's Support Centers in 26 different areas of nuclear security.