Resolution 635 (1989)
of 14 June 1989

The Security Council,

Conscious of the implications of acts of terrorism for
international security,

Deeply concerned by ail acts of unlawful interference
against international civil aviation,

Mindful of the important role of the United Nations
in supporting and encouraging efforts by all States and
intergovernmental organizations in preventing and
eliminating all acts of terrorism, including those involv
ing the use of explosives,

Determined to encourage the promotion of effective
measures to prevent acts of terrorism,

Concerned about the case with which plastic or sheet
explosives can be used in acts of terrorism with little risk
of detection,

Taking note of the International Civil Aviation Organization Council resolution of 16 February 1989, in
which it urged its member States to expedite current
research and development on detection of explosives
and on security equipment,

1. Condemns all acts of unlawful interference
against the security of civil aviation;

2. Calls upon all States to co-operate in devising and
implementing measures to prevent all acts of terrorism,
including those involving explosives;

3. Welcomes the work already undertaken by the
International Civil Aviation Organization, and by other
international organizations, aimed at preventing and
eliminating all acts of terrorism, in particular in the
field of aviation security;

4. Urges the International Civil Aviation Organization to intensify its work aimed at preventing all acts of
terrorism against international civil aviation, and in
particular its work on devising an international régime
for the marking of plastic or sheet explosives for the
purpose of detection;
5. Urges all States, and in particular the producers
of plastic or sheet explosives, to intensify research into
means of making such explosives more easily detectable, and to co-operate in this endeavour;

6. Calls upon all States to share the results of such
research and co-operation with a view to devising, in the
International Civil Aviation Organization and other
competent international organizations, an international régime for the marking of plastic or sheet explosives for the purpose of detection.

Adopted unanimously at the
2869th meeting.
