Pakistan said on Monday it was taking steps to keep a U.S. consulate worker, imprisoned in a local jail for shooting two Pakistanis, safe from harm in a case that has unleashed a diplomatic storm.

U.S. officials have expressed fears about the safety of Raymond Davis as anti-American sentiment has flared after the U.S. national shot and killed two Pakistanis in the eastern city of Lahore in what he said was an attempted robbery last month.

Surveillance cameras monitor the area where Davis, who Washington insists is shielded by diplomatic immunity and must be released immediately, has been locked in a cell isolated from other prisoners, prison sources said.

A team of 36 unarmed guards, who Pakistani officials say have been specially screened, are standing watch in shifts of eight.

Outside the Kot Lakhpat jail in Lahore, where protesters have demanded Davis be publicly hanged, some 75 police officers, a team of provincial rangers and vehicles packed with elite forces stood watch.

We have taken maximum security measures to ensure his protection, Rana Sanaullah, law minister for Punjab province, where Lahore is located, said.

The heightened security underscores the charged nature of the Davis case, which has inflamed already strained ties between two nations which are supposed to be working together to stamp out Islamist militants attacking U.S. soldiers in Afghanistan.

Last week the Lahore high court delayed a hearing on whether Davis had immunity until March 14, prolonging the diplomatic standoff between the two countries and stoking concerns for his safety.

There is good reason for worry in turbulent Pakistan, where rogue members of security forces have at times turned their weapons against government officials.

Last month, Punjab Governor Salman Taseer was gunned down by one of his own police guards. His killer has become a hero for Islamist groups who opposed the governor's moderate political views.

Some analysts believe that elements of Pakistan's security establishment remain linked to Islamist militants in the tribal areas bordering Afghanistan and Pakistan, the very groups the United States is seeking to defeat across the Khyber Pass.

Davis's safety is a concern, a U.S. official said on condition of anonymity.

While some Pakistani officials have signalled they would like to back Davis's immunity, the government so far has said local courts must decide.

Prime Minister Yusuf Raza Gilani told parliament that Pakistan would respect international law but said there was some ambiguity about the case.

My government will not compromise on dignity and sovereignty of the country, he said