Aftermath of the blast in front of the Marriott Hotel in Islamabad. Photo from Voice of America.

Islamabad is the latest target of the Taliban terror campaign. More than 40 people have been killed and more than 70 have been wounded after a suicide truck bomb packed with explosives rammed into the Marriott Hotel in the Pakistani capital today, Geo TV reported. Westerners are feared to be among those killed as the death toll is expected to rise.

The hotel is currently on fire. Officials on the scene expect the casualties to rise to over 100 killed, as people are still trapped in the building and many of those wounded are in critical condition.

Officials initially estimated the bomb contained between 120 and 140 pounds of explosives. The blast then ignited a natural gas leak that set the hotel ablaze, CNN reported. The explosion was powerful enough to reduce cars on the street to "twisted steel" and topple trees in the area. A large crater was left in front of the hotel in the aftermath of the blast.

The five-star Marriott Hotel is popular with Western visitors, and has been the target of attacks in the past. Today's attack is the third bombing at the Islamabad Marriott since 2004. One attack occurred as US Embassy personnel were meeting at the hotel, and wounded two Italian and one American diplomats.

Today's attack is the 13th major strike in Pakistan since Aug. 12. Taliban bombers have struck in Islamabad, Karachi, Lahore, Peshawar, Wah, Dera Ismail Khan, Swat, and Bannu, killing more than 300 Pakistanis and wounding more than 450, according to numbers compiled by The Long War Journal. These numbers do not include casualties sustained during clashes between the military and the Taliban. The Taliban also attempted to assassinate Prime Minister Gilani and the senior US diplomat in Peshawar.

The Taliban has stepped up its promised terror campaign outside of the tribal areas after peace negotiations broke down and the military initiated offensives in Bajaur and Swat.

Baitullah Mehsud, the commander of the Pakistani Taliban, had previously threatened to wage "jihad" and turn the provinces of Sindh and Punjab "into a furnace" if the operations did not cease.

The Taliban insurgency has intensified in Swat, Bajaur, Kohat, Kurram, and other tribal agencies and settled districts in the region. Fighting has been especially heavy in Bajaur and Swat, where the government claimed more than 1,000 Taliban fighters have been killed over the past several weeks.

The military and the government have also fought intense battles along the Indus Highway over the past several weeks. The strategic road connects Peshawar with the southern tribal agencies and districts of the Northwest Frontier Province, as well as the port city of Karachi. The road has been closed since a massed assault on a military outpost near the tunnel on Aug. 21.

Suicide attack in North Waziristan

The blast in Islamabad coincided with a suicide strike against a Pakistani military convoy in North Waziristan. A suicide car bomber rammed into the 30-vehicle convoy as it traveled from Bannu to Miramshah, the administrative seat of North Waziristan.

Ten soldiers were killed and more than a dozen were wounded in the strike.

The military has been under attack from the Taliban and the Haqqani Network after the US fired missiles on a mosque run by Jalaluddin Haqqani.