CAIRO, Sept 13 (Reuters) - The Hamas Islamist group ruling Gaza has been teaching Egyptian Islamists how to plant bombs in cars, Egyptian state television said on Thursday.

Hamas also gave 400 landmines to Egyptian militant groups, said the television. Hamas is an offshoot of Egypt's Muslim Brotherhood. The Brotherhood's Mohamed Mursi was overthrown as Egyptian president by the military in July following mass protests. (Writing by Michael Georgy; editing by Andrew Roche)