The co-owner of Hanif Rajput Catering Service, Salman Ashraf, has been arrested in Faisal Shahzad’s Times Square bombing case.

The news of the arrest came after the US embassy posted a notice on its website that the catering firm co-owned by one of the arrested men and his father may have links to “terrorist groups”.

The embassy named the company as the Hanif Rajput Catering Service, warning that terrorist groups may have ”established links” to the high-class catering company.

Rajput is said to be owned by Rana Ashraf Khan and his son Salman Ashraf.

The Rajput website says Salman Ashraf Khan studied in Houston, Texas, before returning home to help run the family business. It said Rana Ashraf Khan worked for Pakistan International Airlines for 20 years and then started the catering firm.

Rajput cooks for large parties, providing food, cutlery and grand tents at embassy compounds and the homes of the well-to-do in Islamabad and other cities.

In an unusual e-mail message to US residents in Pakistan, the US embassy said U.S. government personnel had been instructed to avoid using the Hanif Rajput Catering Service. The firm is often used by foreign embassies in Islamabad.

The US embassy said the suspicions about the catering company have been shared with Pakistan government agencies.

Unnamed Pakistani officials told news agencies that Salman Ashraf, the co-owner of the firm, was one of four or five men arrested.

Earlier this week, a US delegation to Islamabad including President Barack Obama’s National Security Adviser, Gen James Jones, and the director of the CIA, Leon Panetta, praised Pakistan for its co-operation with the investigation into the attempted Times Square bombing.