Updated

Police in Zanzibar said Tuesday they have arrested 15 people, among them suspects linked to terror groups, in connection to a spate of acid attacks in recent months.

Some of the suspects have links to Al Qaeda and Somali Islamic extremist group al-Shabab, said police commissioner Mussa Ali Mussa, but he offered no evidence.

When pressed for details by the Associated Press about Al Qaeda or al-Shabab connections, Mussa hung up and switched off his mobile phone.

Earlier Mussa said police have seized 29 liters of acid from different people, saying they were illegally in possession of it.

Last week a Catholic priest was attacked and badly injured in the fifth acid attack in Zanzibar since November. Last month two young British women doing volunteer work were injured when acid was thrown in their faces.

Some analysts took issue with the assertion that terror groups may be involved and have a presence in Zanzibar.

Zanzibar is unlikely to have an al-Shabab or Al Qaeda presence, said Ahmeid Rajab, the managing director of the Somali satellite television network, Universal TV. "After all, those radical groups never ever use acid to advance their goals," said Rajab.

Police are looking for another excuse to escape blame for failing to arrest real suspects and instead they are going after innocent people — including school teachers who possess acid as part of their teaching resources, said Rajab.

Mohammed Hafidh, an economist, said he also doubts the validity of the police commissioner's statement.

He said the acid attacks do not bear the hallmarks of Al Qaeda and al-Shabab attacks. The two groups are known for deadly and large-scale attacks.

The acid attacks are affecting tourism, Zanzibar's main economic activity, Hafidh, the economist, said.

Zanzibar draws visitors from around the world attracted by the archipelago's natural beauty and powdery white sand beaches. Zanzibar is also a melting pot of African, Indian and Arabian cultures and influences.