(1) If -

(a) a person does anything outside the United Kingdom as an act of terrorism or for the purposes of terrorism, and

(b) his action would have constituted the commission of one of the offences listed in subsection (2) if it had been done in the United Kingdom,

he shall be guilty of the offence.

(2) The offences referred to in subsection (1)(b) are -

(a) an offence under section 2, 3 or 5 of the Explosive Substances Act 1883 [1883 c. 3.] (causing explosions, &c.),

(b) an offence under section 1 of the Biological Weapons Act 1974 [1974 c. 6.] (biological weapons), and

(c) an offence under section 2 of the Chemical Weapons Act 1996 [1996 c. 6.] (chemical weapons).