At least 47 people have been killed and more than 500 wounded after twin car bombs exploded outside mosques in the northern Lebanese city of Tripoli, according to the health ministry.

The blasts in the predominantly Sunni city went off on Friday, when mosques were packed with worshippers for the noon prayers.

The first explosion hit the Taqwa mosque and killed at least 14 people there. Further deaths were reported from a second blast outside the al-Salam mosque, which the Interior Ministry said was hit by a car laden with 100 kilogrammes of explosives.

The imams of the two targeted mosques were reported to be unharmed and moved to a safe location, according to a local channel. Sheikh Salem al Rafei, a Sunni cleric and outspoken critic of the regime in neighbouring Syria, was leading the prayers at al-Taqwa Mosque.

While the Lebanese government's official position on Syria is one of neutrality, the Lebanese Shia group Hezbollah has openly declared its support for Syria's President Bashar al-Assad, and a number of Lebanese from the city of Tripoli have gone to Syria to fight with the armed opposition.

'I saw bodies'

"We were just bowing down to pray for the second time and the bomb went off. The air cleared, and I looked around me and saw bodies," said Samir Jadool, 39.

Video obtained by local news channel LBC showed the moment of the explosion at al-Salam mosque. The blast ripped through a wall of the mosque, showering clouds of dust on people sitting on prayer mats and sending dozens running out of the building.

Dozens of gunmen deployed on the streets of Tripoli following the attacks, checking people's identity card and driving around in SUVs.

A prominent Salafist sheikh, Dai al-Islam Shahhal, said Sunnis in Tripoli would take security in their own hands going forward, blaming the Syrian regime and its Hezbollah allies in Lebanon for the bombings.

Al Jazeera's Zeina Khodr, reporting from Tripoli, said there have been no claims of responsibility for the attacks.

Residents in the area told her that the bombings, which happened five minutes apart, were specifically targeting the Sunni community.

"It is very tense now in Tripoli. This is a city which is not immune to violence, as it has witnessed intermittent clashes over the last year or so, with parties who support and oppose the Syrian government," she said.

"It is a dangerous time for Lebanon, which is not just split on political lines, but sectarian lines as well. Tensions are high, the country is polarised, and a number of officials are warning that the country is under threat."

She went on to say that in the aftermath of the blast, Lebanese officials were trying to play down the sectarian nature of the attack. "They are saying those who are responsible for the attacks in Tripoli are the same ones responsible for the explosion last week in the southern suburbs of Beirut."

International condemnation

Witnesses at the scene of the blasts said anger was rising among locals, who were shouting out accusations that Assad's government or Hezbollah were behind the attack.

Hezbollah released a statement condemning the blasts and expressing solidarity with the victims, saying they were targets of efforts to fan more violence in Lebanon.

"We consider this the completion of an effort to plunge Lebanon into chaos and destruction," the statement said.

Meanwhile, the international community has strongly condemned the deadly attacks.

Last week, a powerful car bomb ripped through a predominantly Shia neighbourhood in the southern suburbs of Beirut, killing 27 people and injuring over 350.

"There is a lot of fear," Khodr said. "[Residents of Tripoli] are worried, there are reports that there are gunshots being heard in the city. So a very dangerous development at a very volatile time for this country."