ISLAMABAD - The US Embassy in Pakistan has warned American nationals against the possible threats to their residences in the country.

"The embassy has been informed of plans by terror groups to gain access to US citizen residences through visits by construction, maintenance, or utility companies, as well as other technical service providers,"the embassy said Saturday.

The alert was issued days after a group of the Taliban militants massacred nearly 150 children and staff members of an army school in the northwestern city of Peshawar. The security forces have stepped up operations against the militants across the country following the brutal attack on the school.

Pakistan also resumed executions in terrorism-related cases after Prime Minister Nawaz Sharif on Wednesday ended a four-year unofficial moratorium on death penalty.

"US citizens should be extremely cautious about granting access to their residences, even to established companies, for the immediate future,"the US Embassy said in a statement.

"Recent terror attacks in Peshawar and the resulting Pakistan government response may raise the possibility for future threats," it said.

The US Embassy also urged US citizens to vary their times and routes when traveling anywhere in Pakistan, and to avoid travel patterns to such locations that would allow other persons to predict when and where they will be.

"Depending on ongoing security assessments, and as part of routine operational security measures, the US Mission occasionally places areas such as hotels, markets, airports, and/ or restaurants off limits to official personnel,"it said. The statement has also been posted online.