Image copyright AP Image caption A book of condolences is available at the palace for mourners to sign

Large queues formed at the Grand Palace in the Thai capital as mourners paid their respects to King Bhumibol Adulyadej, who died on Thursday.

Thousands, dressed in black, waited to enter to sign a book of condolences at the palace in central Bangkok.

Free buses were laid on to transport mourners from rural areas.

A regent will stand in until the late king's son, Crown Prince Maha Vajiralongkorn, accedes to the throne.

Prince Vajiralongkorn has asked for a delay while he grieves for his father, who at 88 was the world's longest-reigning monarch.

Speaking on state television late on Friday, Deputy PM Wissanu Krea-ngam said the head of Thailand's privy council - currently former Prime Minister Prem Tinsulanonda - would be regent.

"The situation will not be used for long," Mr Wissanu said.

Media playback is unsupported on your device Media caption Thai women mourning the king

Image copyright EPA Image caption Crown Prince Maha Vajiralongkorn (second left) and Princess Maha Chakri Sirindhorn (centre) attended the ceremonies in the palace

The crown prince and Princess Maha Chakri Sirindhorn were among those who paid their respects at the palace.

On Friday, the king's body was transported in a convoy to the Temple of the Emerald Buddha in the Grand Palace from the hospital where he died. Cremation is not expected for several months.

Large crowds of mourners lined the streets, many weeping, as the convoy passed. Millions more watched on TV.

Flags are to fly at half-mast for the next 30 days and official mourning will last a year.

People have been asked to wear black, and avoid "joyful events" during this period.

Image copyright AP Image caption Large queues could be seen from the early hours of Saturday at the Grand Palace

Image caption The official period of mourning is a year

Image copyright Getty Images Image caption Vigils for the king continued into Friday evening

King Bhumibol earned the devotion of Thais for his efforts to help the rural poor and was also seen as a stabilising figure in a country often wracked by political turmoil. Thailand remains under military rule following a coup in 2014.

But critics argued he had endorsed military takeovers and sometimes failed to speak out against human rights abuses.

The crown prince, who is 64, spends much of his time overseas and is much less well known to Thais.

Profile: Crown Prince Vajiralongkorn

Media playback is unsupported on your device Media caption Mourners explain the impact of the death of King Bhumibol

Media playback is unsupported on your device Media caption Strict laws mean little is known about the Thai crown prince

Strict lese-majeste laws protect the most senior members of Thailand's royal family from insult or threat. Public discussion of the succession can be punishable by lengthy jail terms.