British police say they have arrested three more people in connection with the investigation into Monday's deadly bombing after a concert in Manchester.

A statement Wednesday from Greater Manchester Police said only that the arrests came after officers executed warrants in South Manchester. There was no information about how the three men, or a fourth man arrested Tuesday who was only identified as a 23-year-old, might be involved in the attack.

British interior minister Amber Rudd said Wednesday the suicide bomber, who has been identified as 22-year-old Salman Abedi, was "known" by British intelligence services before the bombing. She also told the BBC that "it seems likely, possible, that he wasn't doing this on his own."

Investigators have been working since Monday's attack to determine if the bomber was part of a wider group.

Mark Rowley, who heads the National Counter Terrorism Policing, described the investigation late Tuesday as "making good progress" and following a number of leads. But he said authorities cannot yet say if the Abedi acted alone.

His comments came after a panel that sets the country's terrorism alert level raised it to critical, or the highest step, signaling that another attack was highly likely and could be imminent.

The change is most visible in the deployment of soldiers to help guard certain areas, including major events such as concerts and football matches, in order to free up police officers.

The blast at the conclusion of a concert by American pop star Ariana Grande at Manchester Arena killed 22 people and wounded 59 others. The attacker also died at the site.

Islamic State is claiming it was behind the attack, but neither British nor U.S. intelligence have confirmed that.

英國警方表示又逮捕了三人。他們跟星期一曼徹斯特一場音樂會后發(fā)生爆炸的調(diào)查有關(guān)。

大曼徹斯特地區(qū)警方星期三發(fā)表聲明只說，警察執(zhí)行了在南曼徹斯特的逮捕令，逮捕了那些人。現(xiàn)在還沒有那三名男子以及星期二被逮捕的第四名男子可能跟襲擊事件有什么關(guān)聯(lián)的信息。警方只是說，第四個被逮捕的人23歲。

英國內(nèi)政大臣拉德星期三說，星期一在曼徹斯特一次音樂會后進(jìn)行炸彈襲擊的自殺炸彈殺手先前已經(jīng)受到英國情報部門的注意。拉德在接受英國廣播公司BBC采訪時還說: “看來他這次有可能不是單獨(dú)行動。”

調(diào)查人員自星期一以來一直在試圖確定炸彈殺手是不是某個團(tuán)伙的一部分。

英國全國反恐警察負(fù)責(zé)人羅利星期二晚上說，調(diào)查正在“取得良好的進(jìn)展”，有若干個線索。但是他說，有關(guān)當(dāng)局還不能確定阿拜迪是否是單獨(dú)行動的。

在此之前，英國當(dāng)局一個負(fù)責(zé)掌管全國恐怖預(yù)警級別的委員會將恐怖預(yù)警提升到緊急級別，也就是最高級別，顯示另一場襲擊很有可能發(fā)生，或即將發(fā)生。

為了讓警方騰出更多的警力，英國軍人被調(diào)派協(xié)助守衛(wèi)一些區(qū)域，其中包括重大活動場所，如音樂廳，足球場。

美國流行歌星愛莉安娜·格蘭德音樂會結(jié)束之際發(fā)生的爆炸導(dǎo)致22人死亡，59人受傷。自殺炸彈殺手也當(dāng)場死亡。

伊斯蘭國聲稱襲擊是它策動的，但英國和美國情報部門都沒有證實這一點(diǎn)。

British police say they have arrested three more people in connection with the investigation into Monday's deadly bombing after a concert in Manchester.

A statement Wednesday from Greater Manchester Police said only that the arrests came after officers executed warrants in South Manchester. There was no information about how the three men, or a fourth man arrested Tuesday who was only identified as a 23-year-old, might be involved in the attack.

British interior minister Amber Rudd said Wednesday the suicide bomber, who has been identified as 22-year-old Salman Abedi, was "known" by British intelligence services before the bombing. She also told the BBC that "it seems likely, possible, that he wasn't doing this on his own."

Investigators have been working since Monday's attack to determine if the bomber was part of a wider group.

Mark Rowley, who heads the National Counter Terrorism Policing, described the investigation late Tuesday as "making good progress" and following a number of leads. But he said authorities cannot yet say if the Abedi acted alone.

His comments came after a panel that sets the country's terrorism alert level raised it to critical, or the highest step, signaling that another attack was highly likely and could be imminent.

The change is most visible in the deployment of soldiers to help guard certain areas, including major events such as concerts and football matches, in order to free up police officers.

The blast at the conclusion of a concert by American pop star Ariana Grande at Manchester Arena killed 22 people and wounded 59 others. The attacker also died at the site.

Islamic State is claiming it was behind the attack, but neither British nor U.S. intelligence have confirmed that.

英國警方表示又逮捕了三人。他們跟星期一曼徹斯特一場音樂會后發(fā)生爆炸的調(diào)查有關(guān)。

大曼徹斯特地區(qū)警方星期三發(fā)表聲明只說，警察執(zhí)行了在南曼徹斯特的逮捕令，逮捕了那些人。現(xiàn)在還沒有那三名男子以及星期二被逮捕的第四名男子可能跟襲擊事件有什么關(guān)聯(lián)的信息。警方只是說，第四個被逮捕的人23歲。

英國內(nèi)政大臣拉德星期三說，星期一在曼徹斯特一次音樂會后進(jìn)行炸彈襲擊的自殺炸彈殺手先前已經(jīng)受到英國情報部門的注意。拉德在接受英國廣播公司BBC采訪時還說: “看來他這次有可能不是單獨(dú)行動。”

調(diào)查人員自星期一以來一直在試圖確定炸彈殺手是不是某個團(tuán)伙的一部分。

英國全國反恐警察負(fù)責(zé)人羅利星期二晚上說，調(diào)查正在“取得良好的進(jìn)展”，有若干個線索。但是他說，有關(guān)當(dāng)局還不能確定阿拜迪是否是單獨(dú)行動的。

在此之前，英國當(dāng)局一個負(fù)責(zé)掌管全國恐怖預(yù)警級別的委員會將恐怖預(yù)警提升到緊急級別，也就是最高級別，顯示另一場襲擊很有可能發(fā)生，或即將發(fā)生。

為了讓警方騰出更多的警力，英國軍人被調(diào)派協(xié)助守衛(wèi)一些區(qū)域，其中包括重大活動場所，如音樂廳，足球場。

美國流行歌星愛莉安娜·格蘭德音樂會結(jié)束之際發(fā)生的爆炸導(dǎo)致22人死亡，59人受傷。自殺炸彈殺手也當(dāng)場死亡。

伊斯蘭國聲稱襲擊是它策動的，但英國和美國情報部門都沒有證實這一點(diǎn)。