The Middle East press on Saturday is full of speculation about the motives of those responsible for the attacks in London. Some papers have no doubt that they were carried out by al-Qaeda or a group linked to it.
An Egyptian commentator calls on Muslims to hold an international day of protest against terrorism.
London is the fifth western city to be targeted by al-Qaeda... The organisation's first objective was to demonstrate its ability to attack these cities, thereby creating a climate of insecurity in the West. Its second goal was to overshadow the G8 summit. The global news coverage of the blast contradicted the picture painted by a number of British officials who tried to show that the bombings did not diminish the work of the summit. Al-Qaeda's third objective was to prove that London is not safe enough to host the 2012 Olympics.
Is the party which carried out these blasts directly connected to al-Qaeda or is it a cell of Muslim youths born and bred in Britain? If it is Islamists at all, the likely scenario is that the party which carried out these attacks is a local group made up of youths of the new generation who have been frustrated and influenced by al-Qaeda's ideologies and moral principles. This means that there might be similar attacks on the way... The British government's adoption of every US policy on the occupation of Iraq... has endangered the British people and brought terrorism to the streets of London.
London Al-Quds al-Arabi
All the available evidence indicates that the terrorist al-Qaeda network is behind the London bombing... It is clear from these criminal acts that the perpetrators want to impose a Taleban type of government... We have no doubts that the reaction and response of Britain will not differ from that of the US and Spain, which was characterised by high-level of rationality and fairness... there is no doubt that it will discreetly distinguish terrorists and killers from the genuine peace-loving Muslims... It is important and necessary that Arabs and Muslims in Europe and North America, and probably in the entire world, organise a day of international demonstrations against terrorism... and that they totally reject all ideologies which lead to terrorism.
Egypt's Al-Ahram - commentary by Hazim Abd-al-Rahman
Everyone knows about the terrorist al-Qaeda group. And there is no doubt that this group is controlled by America. America uses al-Qaeda everywhere and at any time to further its own aims - even for manipulating the minds of the British people in an attempt to convince them to abandon their opposition to the UK government's support for America. It would appear that the Zionists and American intelligence organisations are behind the London blasts.
Iran's Jomhuri-ye Eslami
The 11 September terrorists or the July  terrorists in Egypt did not care about the Arabs and Muslims in the US and Britain. They are waging their wars according to their vision and plans. They did not care about the situation of Muslims in Spain nor did they care about the suffering of other Muslims in countries such as Saudi Arabia, Turkey and Indonesia. The reality is that they have abandoned all religions and beliefs.
London Al-Hayat - commentary by Abd-al-Wahab Darkhan
The London bombings prove once again that international terrorism knows no boundaries and stops at nothing. Regardless of whether it does or does not take Islam as a cover for its atrocious designs, international terrorism has come to target all countries indiscriminately.
One can call or say anything about Tony Blair, or describe George Bush's policies as state terrorism, but one cannot justify in any way the criminal and ferocious acts which were committed on 7 July against the public transport system in London and before that in Madrid and on 11 September.
The condemnation of the Saudi government and the fatwa issued by the most important religious scholar describing the London bombing and the killing of the Egyptian diplomat in Iraq as acts of barbarism devoid of true religious belief which Islam does not accept at all is a most significant event... That such a religious decree comes from a Saudi religious leader... and that such a fatwa is enhanced by other fatwas from most Muslim capitals lends it more weight and legitimacy.
The tsunami terrorism caught the Europeans by surprise - this time. London residents witnessed scenes similar to the 11 September incident in America. Britain, and Europe as a whole, got a first hand experience of the dangers of terrorism.
BBC Monitoring selects and translates news from radio, television, press, news agencies and the Internet from 150 countries in more than 70 languages. It is based in Caversham, UK, and has several bureaus abroad.