Oxford United has apologised and withdrawn a new clothing range after it emerged that a shirt bearing the words “United 93” referenced the call sign of one of the aircraft hijacked in the 11 September 2001 attacks.

The design had been intended to mark the club’s founding year of 1893, but the League One side admitted it had failed to consider how the phrase would be read.

The club said the range had been released “without understanding of the historical context and associations.”

United Airlines Flight 93 was one of four commercial aircraft hijacked by al-Qaeda militants on 11 September 2001.

The plane crashed in a field near Shanksville, Pennsylvania, killing all 44 people on board, after passengers attempted to retake control from the hijackers.

It is widely believed the aircraft had been intended to strike the US Capitol Building in Washington DC. The events aboard the flight were later dramatised in the 2006 film United 93.

The wider attacks that day saw two hijacked planes flown into the Twin Towers of the World Trade Centre in New York, causing both to collapse, while a third struck the Pentagon.

In total, 2,977 people were killed and tens of thousands more injured.

Oxford United, which was founded in 1893 as an amateur side called Headington before adopting its current name, said the clothing had been part of its Campus Clothing range.

“It should not have reached the point of sale, and we take full responsibility for not undertaking proper due diligence,” the club said in a statement, confirming the collection had been pulled from sale immediately.

It added that it was reviewing its internal approval processes “to ensure nothing like this happens again.”