ISLAMABAD, Pakistan — The police in Pakistan have charged a United States Embassy security officer with seeking to obstruct an investigation into a car accident involving an embassy vehicle, police officials said on Monday, adding to diplomatic tensions days after an American military attaché was barred from leaving the country over a separate collision.

The arrest was made after an American diplomat’s Toyota hit and injured two people on a motorcycle in Islamabad on Sunday evening, the police said. The injured people were hospitalized, and the diplomat, identified as Second Secretary Chad Rex Ausburn, was briefly detained before being released after the Foreign Ministry confirmed his diplomatic credentials.

But the police said that Taimur Iqbal Pirzada, a security adviser for the American Embassy, sought to obstruct an investigation of the accident and to stop officers from taking the diplomat and his vehicle to a police station. Mr. Pirzada was charged with obstruction and with using assault or criminal force to deter a public servant from carrying out duties. He was released on bail on Monday after appearing in court.

The Islamabad police also registered a case of reckless driving against the motorcycle driver, Nazakat Aslam, on Monday.