Threats against more than one of the three judges who ruled to deny President Donald Trump's so-called Muslim ban are being taken seriously and security details around them have been reinforced.

Local police in San Francisco and the US Marshals Service have increased their patrols and number of officers protecting the threatened judges, law enforcement officials told CNN on Friday (10 February). The news network reports it had no knowledge of the specific threats.

On Thursday the judges ruled unanimously in a federal appeals court in San Francisco that a suspension of Trump's executive order – which bans people from the majority Muslim nations of Iran, Iraq, Libya, Somalia, Sudan, Syria and Yemen from entering the US for 90 days – should remain in place.

The three judges said the ban targeting Muslims presented "significant constitutional questions", and they agreed that courts could consider statements by Trump and his advisers about enacting a ban against Muslims.

The unanimous ruling means that citizens from the countries will continue to be able to travel to the US, despite Trump's executive order.

On 30 January Washington State sought an injunction to stop the order, arguing it harmed the civil rights of the state's citizens and its economy. The state alongside Minnesota are both challenging the constitutionality of Trump's order. The injunction was granted by federal judge James Robart, a mainstream Republican appointed by President George W Bush, in Seattle on Friday 3 February. The panel's decision on Thursday was concerned with Trump's appeal to overturn Robart's ruling.

Trump told reporters that he received news of the decision through the media. Almost immediately after the verdict the president tweeted: "SEE YOU IN COURT, THE SECURITY OF OUR NATION IS AT STAKE!"

Washington state Solicitor General Noah Purcell, who argued the case, said during an interview with CNN that it was ironic the president would say this because "we've seen him in court twice now, and we've won both times".

As the case has unfolded the president has repeatedly called the integrity of the judiciary into question. In a series of tweets on 4 February Trump labelled judge Robart a "so-called judge", and wrote on Twitter that his ruling on the executive order "is ridiculous and will be overturned". He indicated that if a terrorist attack occurred that it would be the court's fault and that terrorists were streaming into the country as a result of the decision.

This lead Trump's nominee to fill an empty seat on the Supreme Court, US Appeals Court Judge Neil Gorsuch, to describe the president's comments about the judiciary as "disheartening" and "demoralising" in a private conversation. A spokesperson for Gorsuch confirmed their accuracy with NBC News.

Trump's latest comments that the US will see the states in court signals that an appeal to the US Supreme Court is imminent. Gorsuch is still awaiting confirmation to join the court. That means any hearing of the case in the near future would be put before a court that is split four to four between democrats and republicans.