Arsenal have completed the signing of Manchester United's Danny Welbeck, with the deal thought to be worth in the region of £16 million.

The 23-year-old has signed a 'long term contract' with the Gunners after spending the entirety of his career with the Old Trafford club.

On a dramatic day of business in the Premier League, the Gunners made their move for the England international after missing out on both Loic Remy and Radamel Falcao in recent days. Reports initially surfaced on Monday afternoon that Welbeck was undergoing a medical with the club, though Arsenal later denied that any deal was in place.

The deal then re-emerged as highly likely with around two hours of the transfer window left. Arsenal requested an extension from the Premier League ahead of the 11pm deadline which was accepted, to allow the final details of the deal to be thrashed through.

Welbeck has signed what is believed to be a five-year contract with United's Premier League rivals in one of the shock moves of an action packed deadline day. Welbeck was deemed surplus to requirements at United by Louis van Gaal, who has brought in Radamel Falcao in perhaps the biggest deal of deadline day. Mexican striker Javier Hernandez also departed Old Trafford for Real Madrid earlier in the day.

Manchester-born forward Welbeck joined his now former club's academy aged eight and scored 29 goals in 142 appearances during his stint with United.