JERUSALEM, Dec. 10 (JTA) — A Jerusalem court has decided to extend indefinitely the detention of a Maryland teen-ager charged with murder until a decision is made on whether to extradite him. The Justice Ministry last week asked the court to honor a formal extradition request for Samuel Sheinbein submitted last month by American officials. Lawyers for the youth have been challenging the request. Sheinbein, 17, fled to Israel in September, shortly after the body of 19-year-old Alfred Tello was found in a Maryland suburb. Maryland police suspect that Sheinbein and another suspect killed Tello and dismembered his body with a saw. Sheinbein hoped to escape trial in the United States by claiming Israeli citizenship through his father, who was born here and left in 1950. Under Israeli law, a citizen cannot be extradited for a crime committed in another country. But after pressure from the United States, Attorney General Elyakim Rubinstein recently stated that the citizenship law does not apply to Sheinbein.