Four British soldiers killed in Afghanistan

LONDON (Reuters) - A fourth British soldier has died of wounds sustained while on patrol in southern Afghanistan, adding to three reported killed earlier in an explosion, the defence ministry in London said on Wednesday.

In the latest incident, a Royal Marine from 45 Commando died after being wounded on patrol in Sangin, in northern Helmand province, on Monday. He died of his wounds after being flown back to the UK for treatment, the Ministry of Defence said.

It takes the number of British soldiers killed in Afghanistan to 149 since the U.S.-led invasion in 2001.

"The death of this brave Marine is a tragedy and his loss will be felt deeply by his family, friends and all those who served alongside him," a spokeswoman for Task Force Helmand said. "We extend our deepest sympathy, thoughts and prayers to them at this terrible time."

Earlier on Wednesday the defence ministry said three soldiers were killed in a blast in the central part of Helmand during an escort operation.

"Today has been incredibly sad for the whole of Task Force Helmand, and particularly for The Rifles. We will all feel the loss of these brave soldiers," the spokeswoman said.

Britain has about 8,000 soldiers in Afghanistan fighting an increasingly bold Taliban insurgency.

(Reporting by Peter Griffiths and Stefano Ambrogi; editing by Elizabeth Piper)