11. There was no warning call prior to the explosion. 12. When it sees an approaching falcon it gives a warning call and the other sandgrouse freeze. 13. A warning call on behalf of the Basque separatist group ETA alerted police before the blast. 14. Warning calls , although exposing a bird and putting it in danger, are frequently given by birds.15. Belloch said that ETA hasn't given a warning call for one of its attacks in many years. 16. Police searched the City Council building for an explosive device after a warning call , news agencies said. 17. The blasts came more than half an hour after one warning call to The Associated Press office. 18. A warning call on behalf of the separatist group gave police enough time to clear the area. 19. Chickens also give a low " warning call " when they think they see a predator approaching. 20. A warning call on behalf of the Basque separatist group ETA alerted police before the first blast.
