NAIROBI, May 8 (Xinhua) -- The Kenyan police on Tuesday issued a terror alert urging Kenyans to remain extra vigilant ahead of Muslims' holy month of Ramadan that begins on May 15.

Police spokesman Charles Owino said intelligence reports indicate that terror groups including al-Shabab are planning to stage attacks on unspecified locations during Ramadan.

"Though the capability of al-Shabab has been greatly downgraded over time, we have credible intelligence suggesting that the militia group is planning to carry out further attacks in the country," Owino said in a statement issued in Nairobi.

"As we approach the holy month of Ramadan, terror groups have issued alerts urging their members to step up attacks during this period. The main terror groups including ISIS, Al-Qaida and al-Shabab have issued 'fatwas' calling for increased attacks during the holy month," Owino added.

He called on members of the public to remain on high alert and be extra vigilant especially in populated public places including hotels, churches, bus stations and schools.

Owino appealed for information on any suspicious individuals either from the borders with Somalia or other parts of the country.

He assured the public that all the information from the public shall be treated with utmost confidentiality.

"It is through the support given to the police by the members of the public that several key members of the of terror groups have been apprehended and many attacks targeting innocent members of public successfully thwarted," Owino said.

He said security forces have already arrested some of the eight suspects whose names were released two weeks ago for allegedly planning to penetrate terror operatives into the country.

The police had placed 160,000 U.S. dollars bounty for the eight suspects who have since been arrested following quick action by the public who volunteered valuable information, said Owino.

He said al-Shabab terror group has in the past planned to carry out attacks during Ramadan especially along the Coastal and Eastern regions and in major towns across the country.