Al-Qaida has developed a seaborne unit to attack targets around the Mediterranean, according to a confidential report from Russian intelligence, one of a cache of secret documents from spy agencies around the world tracking jihadi terrorist groups.

According to the Russians, North African al-Qaida (Aqim – al-Qaida in the Islamic Maghreb) has established a 60-strong team of suicide bombers to plant mines under the hull of ships and to use small, fast craft for kamikaze attacks.

The claim, in a leaked document from Russia’s Federal Security Service (FSB), is one of a string of reports on the rise of Islamic State (Isis) and al-Qaida.

They include a two-month briefing by Omani intelligence estimating that Isis now has up to 35,000 fighters and an income of $1.5m (£1m) a day, reports from United Arab Emirates agents about the Isis leadership structure and a dossier from Jordanian intelligence on confessions extracted from terrorist suspects.

The FSB report on Aqim – which had its origins in Algeria but now poses a threat across north and west Africa and western Europe – is dated February 2011 and claims the movement wants to increase its range to Spain, Italy, France, Britain and Germany as well as Morocco, Algeria, Libya, Mauritania, Senegal, Niger, Nigeria, Chad, Somalia and Kenya.

One of its goals is to mount attacks round the Mediterranean, the FSB says. “To meet this goal the so-called ‘Marine Unit’ (ca.60-man strong) was established: it comprises suicide operatives training in different underwater sabotage techniques (such as planting improvised limpet mines under the hull of a ship) and use of small vessels (schooners) or fast crafts as strike weapons ‘floating bombs’) against seaborne targets.”

Al-Qaida has used such tactics before. A small craft packed with explosives rammed into the American destroyer USS Cole in Yemen in 2000, killing 17 sailors. But there has been no amphibious attack over the past four years. The report may be based more in rumour than fact.

The Omani spies’ briefing on Isis, which erupted on to the international stage last summer and now controls large parts of Iraq and Syria, was given to South African intelligence on 30 November 2014. It described Isis as being mostly made up of Iraqis – the group had its origins in opposition to the US-led occupation of Iraq and in subsequent sectarian conflict with the Shia-led government in Baghdad – with about 20% Syrians.

The estimate of Isis strength by Omani intelligence, which is close to the CIA and MI6 but also to the Iranians, is higher than a CIA one in September of 20,00-31,500 fighters. The Omanis told the South Africans: “[Isis] has increased its number of foreign recruits. The group has more than 6,000 foreign fighters. In terms of financial strength, [Isis’s] daily revenue amount(s) to approximately US$1.5m, mostly from illegal oil sales, ransoms and financial supporters in Gulf States.”

Facebook Twitter Pinterest Samantha Lewthwaite, who was married to the London 7/7 bomber Germaine Lindsay, appears in South African intelligence documents. Photograph: Rex

Another Isis briefing given by intelligence officers in the UAE, one of the Arab supporters of the US-led air strikes against Isis, a week earlier broke Isis down into four main groups: “Ba’athists from the security and intelligence services of former president Saddam Hussein who have become radicalised and now present a core leadership group; the Caucasion or (migrant) battalion led by battle-hardened fighters from the Chechen and Dagestan wars with Russia; Moroccan, Tunisian and Libyan battalions, as well as mixed battalions of fighters from Europe (eg, the UK, France) and elsewhere.”

The UAE intelligence report, which refers to Isis as “Da’esh”, provides details of the full leadership structure, with both real names and jihadi pseudonyms as well as their portfolios. Unlike Oman, the UAE shares the widespread Gulf Arab suspicion of Iran and sees Tehran’s support of air strikes against Isis as part of an attempt to ease its isolation, in particular sanctions from the US and other western countries over its nuclear programme. The UAE intelligence officers blamed its regional rivals for “fuelling the conflict (Qatar and Turkey was specifically mentioned by name but little detail was provided)”.

Jordan, like the UAE, is part of the US-led coalition. But although there was a public outcry after Isis released a video in February showing one of its pilots, Lieutenant Mouath al-Kasaesbeh, being burned alive in a cage, opinion in the state has been divided. Many Jordanians have gone to fight in Iraq and Syria and Jordan’s intelligence agency GID, which works in close collaboration with the CIA, claimed to have “foiled a terrorist plot” to kidnap foreign tourists from hotels and bomb various targets in Amman in 2012.

An internal GID document, dated 24 October 2012 and passed to South African intelligence, reported that 11 people detained over the plot had confessed “during interrogation”. The report, which details the chemical compounds allegedly used to prepare explosives, describes the detainees as having been directly influenced by Abu Musab al-Zarqawi, killed by the US military in Iraq in 2006. Zarqawi founded al-Qaida in Iraq, the precursor to Isis.

South African intelligence, in common with other spy agencies, blames al-Qaida for the radicalisation of Somalia-based al-Shabaab and the expansion of its operations into neighbouring countries. According to one of the spy cables, about 300-500 foreign fighters have gone to Somalia.

Among those monitored by South Africa’s spies for contacts with al-Shabaab or links with Somalia, the spy cables show, was British-born Samantha Lewthwaite, labelled the White Widow by the British media, who was married to the London 7/7 bomber Germaine Lindsay and was wanted in Kenya on charges of possession of explosives.

She makes several appearances in South African intelligence documents marked “counter-terrorism”. She arrived in South Africa on 18 July 2008 and stayed until deported back to the UK on 16 June 2009. She re-entered South Africa on 2 September 2009 under a false passport in the name of Shahidah Bint-Andrews. She then stole the identity of Natalie Faye Webb, a South African living in Britain.

Lewthwaite stayed in South Africa between 2009 and 2011, employed by Crown Pies. In that time, according to her financial statements, she earned £12,000, most of it in 2010. She is recorded as leaving for Tanzania on 20 February 2011. According to South Africa’s State Security Agency in December 2011, she entered Kenya on 26 February 2011 with two men.