Insurgents shot six police officers dead at a checkpoint and a suicide bomber killed three civilians at a shopping bazaar in two attacks in eastern Afghanistan on Sunday.

The attacks came during a surge in hostilities as Afghanistan's spring fighting season begins. This year's is being closely watched because Afghan forces must operate with less support from the international military coalition. With foreign forces due to hand over combat responsibilities to the local forces next year, the current fighting is a test of their ability to take on the country's insurgency.

Reflecting the surge in violence, the Afghanistan NGO Safety Office reported Sunday that insurgent-initiated attacks increased by 47 percent during the first quarter of 2013, compared to the same period last year. The U.S.-led NATO coalition has stopped releasing statistics on insurgent attacks in Afghanistan.

Afghanistan's Defense Ministry said the Afghan army carried out 2,209 military operations during a monthlong period ending Sunday. During that time, 467 insurgents and 107 soldiers were killed, and 362 militants were arrested, the ministry said in a report issued Sunday.

April has been the deadliest month this year for security forces and Afghan and foreign civilians. According to an Associated Press tally, 222 people have been killed in violence around the nation this month, including Sunday's nine fatalities.

The Taliban assault on the checkpoint came early Sunday in the Dayak district of Ghazni province, killing six police officers, wounding one and leaving one missing, said Col. Mohammad Hussain, Ghazni's deputy police chief. One of many Afghan local police forces was running the checkpoint. The forces are recruited at the village level to protect their townships from insurgents and other fighters, including criminals. The local forces are nominally under the control of the Afghan Interior Ministry.

On Friday, Taliban insurgents attacked a local police checkpoint in Andar, a district of Ghazni province neighboring Dayak. They killed 13 officers, according to Sidiq Sidiqi, the Interior Ministry spokesman.

The second Sunday attack hit Paktika province, which borders Ghazni. A suicide bomber detonated his explosives in a shopping bazaar around midday, killing three people and wounding five civilians and two police officers, said Mokhlis Afghan, the spokesman for the provincial governor. Among the dead was Asanullah Sadat, who stepped down as the district's governor two years ago.

Zabiullah Mujahid, a spokesman for Taliban, claimed responsibility for the suicide bombing. In an email to reporters, he said Taliban used the bomber to target Sadat because of his close relations with the Afghan government and the U.S.