PESHAWAR, Pakistan — A U.S. missile strike killed eight suspected militants in northwest Pakistan today, the final day of a year that has seen a major escalation in drone attacks targeting insurgents flowing into neighboring Afghanistan, Pakistani intelligence officials said.

Four missiles struck a convoy of militants traveling by car and by foot near the town of Ghulam Khan in the North Waziristan tribal area along the Afghan border.

It was the third day this week that missiles have struck North Waziristan, part of a ramped-up U.S. campaign to take out al-Qaida and Taliban fighters seeking sanctuary on the Pakistani side of the Afghan border.

Thirty-five suspected militants were killed in missile attacks on Monday and Tuesday, officials said.

More than 110 such strikes, carried out by unmanned drones, have been launched this year — more than double last year’s total.