Media playback is unsupported on your device Media caption The BBC's Jonah Fisher watched as the army arrived at an anti-coup protest

Thailand's ex-PM Yingluck Shinawatra and a number of family members and politicians have been detained, as leaders of Thursday's military coup tightened their grip on power.

Ms Yingluck and scores of politicians from the deposed government had earlier been ordered to report to the military.

She was kept for several hours and then driven to an undisclosed location.

Army chief Gen Prayuth Chan-ocha also met key officials, telling them reform must come before any elections.

Gen Prayuth summoned governors, business leaders and civil servants to the Bangkok Army Club on Friday.

Analysis from the BBC's Jonathan Head in Bangkok

After seven months the tents, stages and all the paraphernalia of protest are coming down in Bangkok's old quarter. With their goal of a military coup achieved, the weary anti-government movement can declare victory and go home. Armed soldiers now patrol their rally sites, next to the monument that commemorates the birth of Thai democracy 82 years ago.

That democracy is now in ruins. When the army mounted a coup eight years ago it did so almost apologetically and promised a speedy return to democratic rule. This coup wears a grimmer face, and there have been no such promises. Instead, land border crossings are being scrutinised to prevent potential resistance leaders escaping. Those the military fears most have been ordered to give themselves up or face arrest. Dozens are being held incommunicado.

No one knows yet what General Prayuth's real intentions are. He has good reason to worry about resistance. The pro-government Red-Shirt movement is far better organised than eight years ago, and could still be financed by former Prime Minister Thaksin Shinawatra's deep pockets.

Six of Thailand's most senior military officers have now been appointed to run the country, with provincial commanders supervising local government.

The BBC's Jonathan Head in Bangkok says that, unlike in previous coups, there have been no promises of a quick return to civilian rule.

Image copyright AP Image caption Thai troops were deployed at key intersections in Bangkok on the second night of curfew

Image copyright Getty Images Image caption There have been some small-scale but angry protests

Gen Prayuth told the meeting: "I want all civil servants to help organise the country. We must have economic, social and political reforms before elections. If the situation is peaceful, we are ready to return power to the people."

The general said the coup was necessary to "quickly bring the situation back to normal".

One local official leaving the meeting, Arkom Theerasak, told Associated Press: "There will be an election but it will take a while. The general didn't say when."

Ms Yingluck, who had been prime minister until being removed by the judiciary this month, had been ordered to report to the military along with more than 100 other politicians, including acting PM Niwatthamrong Boonsongphaisan.

Image copyright AP Image caption Passions also ran high at a former pro-government protest site on the outskirts of the capital

It was unclear whether Gen Prayuth met either of them.

Some 155 politicians have been barred from leaving the country.

Our correspondent says it is unclear how many people have been detained but they have been separated and held incommunicado at different bases.

Reuters quoted a military officer as saying Ms Yingluck, her sister and brother-in-law had been held.

Thai military spokesman Col Werachon Sukhondhadhpatipak told the BBC those detained were all involved in Thailand's political "conflict" and he stressed the army was neutral and impartial in those that it had held.

Media playback is unsupported on your device Media caption Col Werachon told the BBC why the army had detained political leaders

Col Werachon said the detentions should be not be longer than a week and were intended to keep the detainees away from "tension".

Our correspondent says there were some small and angry protests in Bangkok against the coup earlier on Friday but, although a few people were detained, there has been no serious resistance.

On Thursday the military suspended the constitution and banned political gatherings, saying order was needed after months of turmoil.

The US led widespread international criticism of the coup, saying there was "no justification".

Key coup conditions

Curfew nationwide from 22:00 to 05:00

Gen Prayuth to head ruling National Peace and Order Maintaining Council

Senate and courts to continue operating

2007 constitution suspended except for chapter on monarchy

Political gatherings of more than five people banned, with penalties of up to a one-year jail term, 10,000 baht ($300; £180) fine, or both

Social media platforms could be blocked if they carry material with provocative content

Media warned not to carry criticism of army operations

Press fearful after Thai coup

Thailand's armed forces have staged at least 12 coups since the end of the absolute monarchy in 1932.

There has been a power struggle since Ms Yingluck's brother, Thaksin Shinawatra, was ousted by the military as PM in 2006.

Mr Thaksin and Ms Yingluck have strong support in rural areas but are opposed by many in the middle class and urban elite.

The latest unrest began last year, when anti-government protesters embarked on a campaign to oust Ms Yingluck. An election was held in February but was disrupted and later annulled by the judiciary.