Britain will buy 22 Chinook helicopters from Boeing Co. as part of a $1.5 billion investment in new equipment for troops in Afghanistan, the government announced Tuesday.

The announcement came as the Ministry of Defense said that two British soldiers were killed Tuesday by an explosion in southern Afghanistan.

Defense Secretary Bob Ainsworth said the three-year investment plan will be funded by cutting other parts of the military budget. He said the refocused spending will provide troops in Afghanistan with more body armor, tactical radios and night vision goggles, better funding for gathering intelligence, and superior training and equipment for pinpointing roadside bombs.

Britain's military has been repeatedly criticized for deploying troops without sufficient equipment, particularly helicopter support. Helicopters give troops much greater mobility to reach and escape battle zones while minimizing encounters with roadside bombs.

Britain currently has 48 heavy-lift, twin-propeller Chinooks. The first 10 of the new orders are expected to be deployed to Afghanistan by 2013.

Ainsworth said more military spending would be focused on troops deployed in Afghanistan to ensure that "those who put themselves in harm's way on our behalf remain properly supported."

The cost-cutting measures include closing a Royal Air Force base and its squadron of Harrier jump jets, decommissioning two Royal Navy vessels, laying off civilian employees and withdrawing Nimrod MR2 spy planes from service more quickly than planned. Ainsworth said a new-model Nimrod, the MRA4, also would become operational more slowly.

Doubts over the safety of older Nimrods grew following the 2006 deaths of 14 military personnel when their Nimrod exploded following air-to-air refueling over Afghanistan. Investigators found faults in MR2 models' fuel seals and hot air ducts.

The two soldiers who were killed Tuesday died from an explosion near Sangin, in southern Afghanistan's Helmand province. The defense ministry said both were from the 3rd Battalion, The Rifles, and that next of kin have been informed.

Two Afghan soldiers were also killed in the incident.