The Afghan Taliban has sought to reassure the United Arab Emirates that it was not behind an attack in the southern city of Kandahar that killed five UAE diplomats and injured the ambassador, senior Taliban officials said on Thursday.

More than a dozen Afghan and foreign officials were killed last week by a bomb hidden under a couch in the Kandahar governor’s residence in an attack Afghan authorities have blamed on the Taliban and Pakistani intelligence services.

However the Taliban has denied responsibility, instead accusing “covert intelligence circles” close to the government of carrying out the attack to damage relations between the insurgents and a friendly Arab government. No claim of responsibility has been made.

Although the insurgents have frequently targeted Afghan government officials, the attack on diplomats from a Muslim country with which the Taliban has previously had good relations came as a major shock, prompting the insurgent movement to seek to reassure UAE authorities.

The UAE was one of the few countries to recognize the former Taliban government in the 1990s although it broke relations in the wake of the Sept. 11 attacks on U.S. targets in 2001. The United States had demanded the extradition of al Qaeda leader Osama bin Laden from Afghanistan for involvement in the attacks but the Taliban refused.

A number of senior Taliban members live in Qatar, where the movement opened a political office in 2013. Other members are also believed to be living as private citizens in the UAE.

A senior Taliban member based in Qatar said the movement was planning to send a delegation to mourn the slain diplomats and explain that it was not involved.

“We have very cordial relations with some of the Islamic world including the UAE and we would never want to target them,” he said.

“We have targeted a number of diplomats and foreign missions in Afghanistan and there were several occasions we could have attacked diplomats from Islamic countries but we didn’t as they are our friends,” he said.

There was no immediate word from UAE officials.

In Kandahar, authorities are continuing an investigation into the attack, which injured the provincial governor and killed his deputy.

Kandahar police chief General Abdul Raziq, one of the most formidable anti-Taliban commanders who himself narrowly escaped the attack, said that around 20 people had been detained for questioning, including construction workers and government employees including a cook and guards.

He said a UAE investigation team, including specialists from Britain, had been in Kandahar but had left the city.

(Additional reporting by William Maclean in DUBAI, Sayed Sarwar Amani in KANDAHAR; Writing by James Mackenzie; Editing by Alison Williams)