Armed Tanzanians are seeking to establish a base in Mozambique, police said on Friday, after the arrest of dozens of suspected militants from Tanzania in connection with deadly Islamist attacks across the border.Over the last year, more than 50 people have been killed in gun, grenade and knife assaults in a growing jihadist insurgency in Mozambique's northern province of Cabo Delgado.Some 50 Tanzanians are among 180 suspects on trial over the attacks."These criminals want to establish a base in Mozambique. But they are fooling themselves as we have good relations with Mozambique and other neighbouring countries," said police chief Simon Sirro, addressing a press conference in Dar es Salaam.Sirro said the Tanzanians, including young girls, were part of a group responsible for several murders of police officers and administrative officials in Tanzania's eastern Pwani province in 2016 and 2017.The motives of these attacks were unclear and Tanzanian officials are hesitant to point the finger at religious extremism, an extremely sensitive topic in the country.After the killings in Pwani, President John Magufuli hinted at the motive, saying: "There is no religious faith that teaches people to kill."Sirro said police recently arrested 104 members of this group trying to enter Mozambique."As you know there are those we have arrested, there are those who have been killed in clashes with police ... some managed to cross the border" into Mozambique, said Sirro."They hide in the forests, learn how to use weapons of war such as the AK47. This trend comes from foreign countries, we don't have this in Tanzania," he said.Some 60% of Tanzanians identify as Christian and 36% as Muslim, according to a 2010 survey from the Washington-based thinktank, the Pew Research Centre.The country has not had the same struggles with extremism as seen elsewhere in the region, with the only high profile attack the 1998 bombing of the US Embassy in Dar es Salaam.Militants linked to Somalia's Al-Qaeda affiliated Al-Shabaab are believed to be active in the country and in 2016 a video circulated of a group of men pledging allegiance to the Islamic State group.There have been smaller scale attacks - however it is often unclear whether this is linked to criminal activity rather than Islamism.The semi-autonomous islands of Zanzibar, with a majority Muslim population, has been a hotbed of religious tensions, with Islamists blamed for setting churches on fire, attacking Christian leaders and carrying out an acid attack on two British girls in 2013.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook.