The count of dead and wounded is rising fast in a series of terror attacks on Israeli targets Sunday morning, ranging from a bus blast in Haifa to gunfire attacks in Jerusalem and Gaza.

At least 15 people were killed and more than ten remain in critical condition after a bomb exploded in a bus shortly after noon in central Haifa. Dozens more are suffering from milder wounds and shock.

Police do not yet know whether the attack was perpetrated by a suicide bomber, or through an explosive device left on the bus.

The #16 bus was traveling from the Neve Shaanan neighborhood to Hadar. It blew up at the Khalisa neighborhood, specifically 100 meter before Hagiborim intersection. It burst into flames, continued downhill and crashed into a wall, an eyewitness told Israel Radio.

An earlier report that the bus was a #18 was erroneous.

An eyewitness says the bus is a charred wreck and that several bodies are still inside.

Early reports of a second explosion on another Haifa bus were unsubstantiated. A nearby bus had been damaged by the shock waves from the explosion of the first bus.

Emergency numbers at hospitals: Bnei Zion 1255 145; Rambam 1255 144; Carmel 1255 142. Emergency number at Haifa municipality: 12-12-466-106.

Three people were wounded in gunfire aimed at the Gilo neighborhood of Jerusalem at about 13:15 Sunday afternoon.

One person was killed and four wounded in a shooting attack on a Jewish settlement in the Gaza Strip early Sunday morning, after ten people were killed and more than 180 wounded in three blasts in Jerusalem Saturday night.

One Israeli killed, four injured in attack near Gaza settlement

An Israeli man was killed and four people injured Sunday morning when two Palestinian gunmen opened fire on passing cars near the northern Gaza settlement of Alei Sinai.

After firing on the car, the gunmen fled to a firing range used by the IDF and which is located between the settlements of Alei Sinai and Nisanit. A gun-battle ensued during which an IDF tank found and killed both gunmen. Army Radio reported that the two were dressed in IDF uniforms.

In a report published in the Qatari Television station Al-Jazeera, Hamas's military wing, The Al-Qassem Brigade took responsibility for the Alei Sinai attack. It also released the names of the attackers: Jihad Musri, 17 and Muslama Araraj from Palestinian town of Beit Lahia in Gaza.

Three mortars were fired at settlements in Gaza in the course of Sunday morning. There were no injuries.

Security forces arrested nine Palestinians overnight Sunday near the Islamic University in the town of Abu Dis near Jerusalem. Those arrested are thought to be relatives of the suicide bombers who carried out the attacks late Sunday night in Jerusalem, killing 10 people.