WASHINGTON - A surge of foreign troops into Afghanistan has dealt a blow to the Taliban insurgency but total violence has risen since last fall, the Pentagon said on Friday.

The Pentagon, in a twice-annual report to the U.S. Congress, said the increase in overall security incidents, which includes roadside bombs, direct fire and other violent acts, was due in part to the surge of foreign troops, stepped-up targeting of insurgent safe havens, and mild winter weather.

"The surge in forces and an increased operational tempo have enabled (the NATO-led force in Afghanistan) to disrupt and degrade the insurgency's capabilities, contributing to a loss of Taliban influence in key areas," the report said.

As U.S. President Barack Obama sent an additional 30,000 troops to Afghanistan, violence hit its highest level in 2010 since the war began almost a decade ago.

Pentagon warned that "hard fighting" was likely ahead in 2011 as the Taliban, adapting its techniques to match intensified attacks from foreign adversaries, would try to regain areas of south Afghanistan that they had lost in 2010. The report, which covers the period from Oct. 1, 2010, to March 31, 2011, also warned that political challenges and slow progress in improving governance could jeopardize gains made in security. (Reuters)