RIYADH: At least four people died in a suicide bombing near Masjid-i-Nabvi (PBUH) in Madinah on Monday night.

"Security forces suspected a man who was heading towards Masjid-i-Nabvi (PBUH) as he passed through a visitors' parking lot," the Saudi interior ministry said in a statement.

"As they tried to stop him, he blew himself up with an explosive belt causing his death, and the death of four security personnel," said the statement, adding that five others were injured. Security forces cordoned off the area after the attack.

Saudi media said the attacker was intending to strike the mosque when it was crowded with thousands of worshippers gathered for evening prayers.

A news channel showed images of a fire raging in a parking lot near the mosque, which was packed Monday evening with worshippers. Al Arabyia's correspondent said worshippers were unhurt following the attack.

State-run news channel al Ekhbariya showed footage of Saudi King Salman's son and Governor of Madinah Prince Faisal bin Salman visiting security officers wounded in the blast and the site of the explosion.

A video sent by a witness to the aftermath of the Madinah bombing showed a large blaze among parked cars in the fading evening light, with a sound of sirens in the background.

The sprawling mosque where the Prophet Muhammad (PBUH) is buried is visited by millions of Muslims from around the world each year during pilgrimages to Makkah.

It was the third suicide attack in Saudi Arabia on Monday, with two others earlier reported near a Shia mosque in Qatif and the United States embassy in Jeddah.

There were no immediate claims of responsibility for the three attacks.

Cairo-based Al-Azhar condemned the attacks and stressed "the sanctity of the houses of God, especially the Masjid-i-Nabvi".

Saudi Arabia's supreme council of clerics said the attacks "prove that those renegades... have violated everything that is sacred".

The head of Saudi Arabia's Shura Council, the kingdom's main advisory body, said the attack was "unprecedented".

"This crime, which causes goosebumps, could not have been perpetrated by someone who had an atom of belief in his heart," Abdullah al-Sheikh said.

Since late 2014, Saudi Arabia has been hit by bombings and shootings claimed by militant groups but multiple attacks on the same day are unusual.

Pakistan has strongly condemned the terrorist attacks in the Kingdom of Saudi Arabia resulting in loss of lives and injuries.

'Never imagined this could happen here'

Altayeb Osama, a 25-year old Sudanese visitor to Madinah and resident of Abu Dhabi, said he heard two large booms about a minute apart as he was heading toward the mosque for sunset prayers. He said police and fire trucks were on the scene within seconds.

"It was very shocking that such a thing happened in such a holy place for Muslims, the second holiest place in the world. That's not an act that represents Islam," Osama said.

"People never imagined that this could happen here."

'Sounded like a building imploded'

Qari Ziyaad Patel, 36, from Johannesburg, South Africa, was at the mosque when he heard a blast just as people were breaking their fast.

Many at first thought it was the sound of traditional, celebratory cannon fire, but then he felt the ground shake.

"The vibrations were very strong," he said. "It sounded like a building imploded."

Two blasts outside Shia mosque in Qatif

Earlier, In Qatif, an eastern city that is home to many members of the Shia minority, at least one and possibly two explosions struck near a Shia mosque.

Witnesses described body parts, apparently of a suicide bomber, in the aftermath.

A resident of the city reached by telephone said there were believed to be no casualties there apart from the attacker, as worshippers had already gone home to break their fasts. Civil defence forces were cleaning up the area and police were investigating, the resident said.

“Suicide bomber for sure. I can see the body” which was blasted to pieces, said a witness.

Foreign bomber strikes near US consulate in Jeddah

A foreign suicide bomber blew himself up near the American consulate in Saudi Arabia's western city of Jeddah in the early hours of US Independence Day on Monday.

The Saudi interior ministry said the bomber was a Pakistani citizen residing in the kingdom.

Two security officers were slightly wounded, the ministry said.

The American embassy in Riyadh reported no injuries among US consulate staff.

General Mansour al-Turki, the interior ministry spokesman, told Saudi-owned Al-Arabiya television that the bomber was not Saudi but a “resident foreigner”.

All the three incidents of explosions — targeting US diplomats, Shia worshippers and the security headquarters of Masjid-i-Nabvi (PBUH) — follow days of mass killings claimed by the Islamic State group, in Turkey, Bangladesh and Iraq.

The attacks all seem to have been timed to coincide with the approach of Eidul Fitr.

Pakistan condemns Saudi attacks

President Mamnoon Hussain and Prime Minister Nawaz Sharif have also strongly condemned the terrorist attacks in Saudi Arabia, Radio Pakistan reported.

The president expressed solidarity with Saudi King Salman bin Abdulaziz Al Saud and extended his sympathies to the bereaved families.

He stressed the need for the Muslim world to unite together and adopt a strategy against terrorism.

Army Chief Gen Raheel Sharif on Tuesday called Saudi Defence Minister Prince Muhammad bin Salman over phone and condemned the Saudi attacks.

An Inter-Services Public Relations communique said the army cheif sympathised with the families of attack victims, adding, "We stand shoulder to shoulder with our Saudi brothers in fighting the menace of terrorism."

Foreign Office Spokesman Nafees Zakaria said the Pakistani government extends its condolences to Saudi Arabia over the loss of lives in recent attacks.

"Our hearts go out to the bereaved families and we wish a speedy recovery for the injured," he said.

Zakaria assured the Saudi government of Pakistan's support and reiterated its commitment to the safety, security and territorial integrity of Saudi Arabia.

The FO spokesman reiterated Pakistan's stance on terrorism, adding that Pakistan condemns terrorism in all its forms and manifestations.

With additional reporting by Mateen Haider.