Elusive Egyptian chemist Midhat Mursi was said to be exploring the use of poison gas in mass terror when last seen. Mursi, who has a degree in chemical engineering, was researching deadly compounds and gassing dogs in Afghanistan at the time. The FBI and other US agencies are interested enough in Mursi to have posted a US$5 million reward this year for his capture. Egypt's government reportedly is interested enough to have seized and locked up his two sons in an effort to track down the father. The US reward poster says the alleged bombmaker, also known as Abu Khabab, literally "Father of the Trotting Horse," may be in Pakistan. But "we don't think there's really a good fix on where he is," FBI counterterrorism analyst Donald Van Duyn said in a Washington interview.