Pakistani intelligence officials say a U.S. drone strike in northwest Pakistan has killed a senior member of the militant Haqqani network.

Thursday's attack in North Waziristan reportedly killed Jalil Haqqani, a logistics coordinator for the al-Qaida-linked group. At least three other militants were also killed when an unmanned aircraft fired missiles at a compound near the region's main town, Miran Shah.

Officials say Jalil was very close to Sirajuddin Haqqani, the leader of the militant network, which is reportedly based in North Waziristan.

Hours later, Pakistani officials say a second drone strike on Thursday killed at least three militants in the South Waziristan tribal region near the Afghan border.

The attacks occurred as the U.S. special representative to Pakistan and Afghanistan, Marc Grossman, held talks with Pakistani leaders in Islamabad.

Both sides pledged to strengthen ties in the fight against terrorism. Prime Minister Yousuf Raza Gilani said the cooperation must also expand to areas such as trade, water, power and infrastructure. Grossman and Pakistani leaders also discussed the situation in Afghanistan.

Thursday's talks come amid heightened tensions between Pakistan and the United States.

Last month, senior U.S. officials accused Pakistan's military spy agency of helping the Haqqani network launch attacks in Afghanistan, including an assault on the U.S. Embassy in Kabul.

In other violence in Pakistan, gunmen opened fire on a convoy of at least five NATO oil tankers Thursday in the Shikarpur area of southern Sindh province. The trucks caught on fire.

Militants often attack vehicles carrying fuel and other supplies to international troops in neighboring Afghanistan.