Four U.S. soldiers killed in Afghanistan

KABUL, Afghanistan, July 20 (UPI) -- Four U.S. soldiers died in a roadside explosion in eastern Afghanistan as a major anti-militant campaign by the Marines and British troops was under way.

Details of Monday's attacks were not immediately available but The New York Times reported the deaths of the four pushed the U.S. death toll in Afghanistan this month to 30, making it the deadliest month since the 2001 invasion. The killings also pointed to the higher level of accuracy the militants have achieved with their roadside bombs.

U.S. Marines and British troops, along with Afghan security forces, have been involved in a major campaign for the past three weeks to regain control of the Helmand Province in the southwest from the Taliban, who use opium cultivated in the region to finance their activities.

The Times said as the campaign goes on, the critical issue has become the increasing sophistication of the roadside explosives used by the militants.

July also marked a deadly month for all NATO-led forces in the country, with 56 troops killed so far -- far more than the previous high of 46 in June and August of 2008, the Times said.

The Los Angeles Times quoted U.S. military officials as predicting a bloody summer in Afghanistan as more U.S. troops venture into militant-controlled areas. The eastern region near the border with Pakistan's tribal region has become especially dangerous lately.

A British soldier died Monday in southern Afghanistan, raising the British toll this month to 16.