PESHAWAR (REUTERS) - A United States drone strike killed at least 17 people in Pakistan's restive border region early on Wednesday, Pakistani security officials said, in the biggest such attack this year, and the second since Prime Minister Nawaz Sharif took office.

Most of those killed were fighters for the Haqqani network, according to three Taleban commanders and security officials.

Two missiles hit a house near the main market in Miranshah, the provincial capital of the tribal region of North Waziristan.

The region is considered a Taleban stronghold.

Many were wounded in the attack, local tribesman Kaleemullah Dawar said, but rescuers delayed assistance for fear of falling victim to a second attack, a common tactic with drone strikes.

"It was not possible for the people to start rescue work for some time, as the drones were still flying over the area," Mr Dawar said.

Mr Sharif, who won elections in May, has called for an immediate end to US drone strikes on the grounds that they are a breach of Pakistan's sovereignty. The US says it is attacking militants in areas the Pakistani army cannot reach.

A drone strike in May killed the Pakistani Taleban's second-in-command and six others.