Turkish Prime Minister Recep Tayyip Erdogan said two car bombs which killed at least 20 people in Istanbul were aimed at destabilising the country. Erdogan cut short a visit to northern Cyprus in the wake of the bombings at the city's synagogues. The number of the people killed in the blasts reached 22. At least six of those who died were Jewish, according to members of the local community. Israel has denounced the blasts as "criminal terror attacks". Israeli Foreign Minister Sylvan Shalom is scheduled to visit Istanbul on Sunday.Turkish authorities have detained four people in connection with near simultaneous bomb explosions near two Istanbul synagogues. Authorities believe the Saturday attacks were likely carried out by terrorists from outside the country, possibly al Qaeda. Outside one of the synagogues, a surveillance camera taped a man parking a station wagon in the street. Moments later, the vehicle exploded.