The deputy mayor of Kabul was arrested Saturday for alleged misuse of authority, a senior Afghan official said, part of a crackdown in the wake of massive international criticism of corruption in President Hamid Karzai's government.

Wahibuddin Sadat was taken into custody at Kabul International Airport when he returned from Mecca, Saudi Arabia, according to deputy Atty. Gen. Fazel Ahmad Faqiryay. He said the deputy mayor was accused of misuse of authority but did not elaborate.

The arrest comes five days after an Afghan court convicted the capital's mayor, Abdul Ahad Sahebi, of awarding a contract without competition and sentenced him to four years in jail. He was also ordered to repay more than $16,000 involved in the contract.

Sahebi has appealed and is refusing government orders to give up his post.

International pressure is mounting to clean up Afghanistan's notoriously corrupt and ineffectual government, which barely functions outside Kabul, following a fraud-marred presidential election last August. Karzai was proclaimed the winner last month after his last remaining challenger dropped out of a planned runoff, saying the ballot would not be fair.

Public outage over corruption and bad governance is considered one of the main reasons for the rise of the Taliban, who were ousted from power in the U.S.-led invasion of 2001.

President Barack Obama has ordered 30,000 reinforcements to Afghanistan to try to turn back the Taliban, despite widespread concern that the military cannot prevail without fundamental improvements in the Afghan government.

Also Saturday, three Taliban fighters were killed when a roadside bomb they were planting exploded in Helmand province, local administration chief Abdul Ahad Khan said.

Four Afghan private security guards were killed Saturday when their car hit a roadside bomb elsewhere in Helmand, Khan said.