Lahore (Agencies): American official Raymond Davis arrested for double murder may have to spend at least three more weeks in custody with a Pakistani court on Thursday putting off to next month the case to decide his diplomatic status, escalating the tense standoff between the two countries over the issue.

The Lahore High Court adjourned the case till March 14 after Deputy Attorney General Naveed Inayat Malik, who represented the federal government at Thursday's hearing, told its Chief Justice Ijaz Ahmad Chaudhry that Foreign Ministry needed more time to submit a response on the diplomatic status of Davis.

Another court extended his judicial remand till March 3.

The US has insisted that 37-year-old Davis has diplomatic immunity and demanded that he should be released immediately.

"We believe that diplomatic immunity (to Davis) is a fact. From our standpoint, it is not a matter in dispute. It's certainly not a matter that should be resolved by courts in Pakistan," State Department spokesman P J Crowley said in Washington.

Lahore High Court Chief Justice Ijaz Ahmad Chaudhry put off the hearing of several similar petitions asking the court to direct authorities to prosecute Davis after Deputy Attorney General Naveed Inayat Malik said the Foreign Ministry needed more time to determine Davis' diplomatic status.

Khwaja Haris, the Advocate General of the Punjab government, told the Lahore High Court that the federal government alone could determine whether Davis has diplomatic immunity. He argued that the Vienna Convention does not give blanket immunity to persons involved in heinous crimes.

Davis, arrested on January 27 after he shot and killed two Pakistani men who he claimed were trying to rob him, had been charged for murder by police, he remarked.

The American official claimed that he had fired in self defence, but this was rejected by police.

Three FIRs were registered and police had conducted an investigation, following which Davis had been charged for murder, Haris said.

The Punjab government has fulfilled all legal requirements in the case, he added.

Haris said a "serious question" had arisen regarding Davis' status as US authorities first stated that he was a member of the staff of the consulate Lahore but later contended he was a member of the technical staff of Embassy in Islamabad.

After hearing the arguments of the lawyers for the federal and provincial governments, Chief Justice Chaudhry said: "How can the court proceed further in the case till the Foreign Office tells us about his (Davis') diplomatic status?"

He subsequently adjourned the matter till March 14.

In a related development, judicial magistrate Aniq Anwar extended Davis' judicial remand for illegal possession of a weapon for 14 days at the request of the prosecutor general.

Davis was not produced in the magistrate's court due to security concerns and the hearing was conducted through video-conferencing.

He will be presented in the trial court on February 25 to face murder charges.

The High Court is hearing several similar petitions asking it to direct authorities to prosecute Davis.

The prosecution department of Punjab has filed a request in court to request that Davis' trial be held in Kot Lakhpat Jail because of security reasons.

An application was also filed today by lawyer Azhar Siddique to make former Foreign Minister Shah Mahmood Qureshi party to the case as he had contended that the Foreign Office was of the opinion that Davis does not enjoy "blanket immunity".

He is being held in Kot Lakhpat Jail and police have accused him of murder in a charge-sheet filed in a lower court.

The charge-sheet also rejected Davis' claim that he had acted in self-defence. An application was also filed in the Lahore High court today by lawyer Azhar Siddique to make former Foreign Minister Shah Mahmood Qureshi party to the case as he has disclosed that the Foreign Office was of the opinion that Davis does not enjoy "blanket immunity".

Deputy Attorney General Malik informed the High Court that Davis' name had been included in the government's Exit Control List to bar him from leaving Pakistan.

Concerned authorities, including the Federal Investigation Agency, Director General Passport, Director General of the Inter-Services Intelligence, Military Intelligence and Intelligence Bureau, had been notified in this regard, he said.

Pakistan's top leadership, including President Asif Ali Zardari, have said Davis' case is already in the courts and will be decided according to the country's laws.

US President Barack Obama waded into the diplomatic row for the first time on Tuesday, saying Pakistan should release Davis on grounds of diplomatic immunity.

The issue has taken Pakistan-US relations to a new low and American lawmakers have warned that the detention of the official could affect civil and military aid.

The US has also postponed a trilateral meeting with Pakistan and Afghanistan scheduled for this month due to the row.

Qureshi, who was not reallocated the foreign affairs portfolio during a recent shake-up of the cabinet apparently due to his stand on Davis' issue, yesterday reiterated his contention that he believed the American does not have "blanket immunity".

Meanwhile, civil society activists organised a protest on the issue of Davis for the first time outside the US consulate in Lahore.

Earlier, religious parties and cricket-turned politician Imran Khan's Tehrik-e-Insaaf had held rallies against the US on the issue.

The civil society activists warned the government not to hand Davis over to the US.