A gang of thieves held up a security van transporting cash from the Mount Parnes Casino yesterday and made away with an estimated 1.6 million euros in one of the largest hauls taken in a robbery, according to authorities. Police said that at about 12.30 p.m. a gang of four or five armed men stopped the security van about 20 kilometers north of Athens by blocking the road. The thieves then rammed the security van with a stolen truck, smashed the bulletproof windscreen with sledgehammers and forced the driver and guard, who did not resist the attack, to open the vehicle. The thieves, all wearing hoods, took four or five sacks full of cash and fled from the scene in a stolen car. Police, who have launched a manhunt for the culprits, described the heist as being very well organized. No one was hurt in the holdup.