Afghanistan - A suicide bomber killed at least 23 people, including the country's deputy head of intelligence, in an attack near a mosque in eastern Afghanistan on Wednesday, officials said.

Lutfullah Mashal, governor of Laghman province who escaped injury in the attack, told Reuters the bomber burst from a shop and blew himself up while officials were getting into cars outside the mosque in the provincial capital Mehtar Lam.

He said the 23 dead included two provincial officials as well as Abdullah Laghmani, deputy head of the powerful National Directorate for Security and one of the highest-ranking security officials in President Hamid Karzai's government to be killed.

It is obviously the work of the Taliban who are trying to destabilize Afghanistan by trampling Islamic values, Mashal said. He said 36 people were wounded.

Violence in Afghanistan this year reached its highest level since the Taliban were ousted by U.S.-backed Afghan forces in 2001, escalating further in the runup to a presidential election last month, the result of which has yet to be announced.

The election was a major test for Karzai after eight years in power and for U.S. President Barack Obama, who has sent thousands of extra troops to Afghanistan this year a new strategy to defeat the Taliban and stabilize the country and neighboring Pakistan.

A Taliban spokesman, Zabihullah Mujahid, said the Islamist group had sent a suicide bomber to carry out the Laghman attack.

The presidential palace confirmed the death toll, including Laghmani. By conducting such a vicious act and killing of religious scholars and innocents, the terrorists showed that they trample Islamic values on the orders of their masters and can go to any extent in committing a crime, Karzai said in a statement.

A Reuters witness in Mehtar Lam, a town in mountains about 100 km (60 miles) east of Kabul, saw a pickup truck carrying wounded people covered in blood. Eight ambulances left the scene headed toward Jalalabad, the nearest major city.

The commander of the 103,000-strong U.S. and NATO force in Afghanistan said this week the situation was serious and deteriorating and existing military strategy must be changed.

OPIUM CULTIVATION, PRICES FALL

In rare good news, the United Nations reported that land under opium poppy cultivation had fallen by nearly a quarter this year. The biggest fall was in Helmand, Afghanistan's most violent province and site of major U.S. and British offensives this year.

Afghanistan produces 90 percent of the world's opium used to make heroin. Political leaders and military commanders believe the illegal trade funds the insurgency, fuels corruption and undermines the government they are fighting to support.

Prices for opium have tumbled, persuading farmers to switch to other crops, and 800,000 fewer Afghans now work in the trade, the U.N. report said. Drugs now make up just 4 percent of Afghanistan's economy, down from 27 percent in 2002, it said.