As many as 12 persons were injured after two cars hit two other cars that were already in an accident and a rescue van Sunday. The pile-on occurred near Urse toll booth on the Pune-Mumbai Expressway. Among the injured are two members of an IRB Infrastructure Development Ltd rescue team that had rushed to the spot after the first accident. The condition of two others is stated to be critical. The first accident took place around 4.30 pm when an Indica car hit a Swift car from behind near Urse toll booth,about 30 km from the city. In a few minutes,a rescue team from the IRB,which maintains the expressway,and a team from the Lokmanya Hospital reached the spot and started treating the injured. After a few more minutes,as the rescue operation was on,two more rammed into these cars and also hit the rescue van. The 12 injured are being treated at Lokmanya Hospital in Nigdi and Pawana Hospital near Somatane. Some of the injured have been identified as Megha Naik (33) and Amit Naik (35) of Sangvi,Shankar Ghare of Ozarde,Santosh Ghare,Veena Bagadiya,Anil Nirmal and Sandeep Yadav. Megha Naik and Shankar Ghare have been admitted to the intensive care unit of Lokmnaya Hospital and are said to be critical.