Islamabad, Dec 26 (IANS): Amid heightened security in Islamabad, the US Embassy has issued an alert for its staff, urging them to refrain from non-essential, unofficial travel in the city, and to specifically avoid the Marriott Hotel where an attack is possible, media reports said.

As per the security alert issued by the Embassy, the US government was "aware of information that unknown individuals are possibly plotting to attack Americans at the Marriott Hotel in Islamabad sometime during the holidays" and prohibited its staff from visiting it, the Dawn reported.

The five star hotel had been targeted in 2008 when a suicide bomber rammed a truck packed with 600 kg of high explosives into its outer gates, killing at least 60 people and bringing down a part of the structure.

The Embassy also urged all its personnel to refrain from "non-essential, unofficial travel in Islamabad throughout the holiday season" due to the red alert declared in the city and the ban on public gatherings.

It advised them to exercise vigilance at events, places of worship, and avoid locations with large crowds, review their personal security plans, carry identification and follow requests from law enforcement, be aware of their surroundings and monitor local media for updates.

Dawn said that it has reached out to the Foreign Office and Interior Ministry for comment.

Meanwhile, the Islamabad police raised security to a high alert in the capital after a suicide bombing in the capital killed a policeman and wounded six others.

The police said that checking was increased at all entry and exit points and requested people to cooperate with inspections.

The capital administration had subsequently banned all types of gatherings, especially activities related to the upcoming local government elections, for two weeks and declared a high alert in the city for 48 hours, the Dawn reported.