Over two dozen countries, including Pakistan, will take part next week in a full-scale test of the Indian Ocean`s tsunami alert system, using the 2004 Sumatra quake as the basis for the exercise, Unesco said on Thursday.

Exercise IOWAVE 11 will re-enact the seismic events of Dec 26, 2004, simulating a 9.2-magnitude quake that occurs northwest of Sumatra, sending waves across the Indian Ocean that strike the coast of South Africa 12 hours later.